Heroku Rails app deployment successful but application error

#問題
タイトル通りです。Herokuへのデプロイはできるが`heroku open`を打つと下記が。。。
![Screen Shot 2017-02-12 at 12.46.59 AM.png](https://qiita-image-store.s3.amazonaws.com/0/87666/1085d0d0-df71-8db2-06dc-8ed84d04a647.png)

##まずは`heroku logs`

```
2017-02-12T08:34:34.349522+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:353:in `wrapped_app'
2017-02-12T08:34:34.349556+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
2017-02-12T08:34:34.349537+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:282:in `start'
2017-02-12T08:34:34.349539+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/server.rb:79:in `start'
2017-02-12T08:34:34.349553+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
2017-02-12T08:34:34.349520+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/server.rb:59:in `app'
2017-02-12T08:34:34.349556+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
2017-02-12T08:34:34.349558+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
2017-02-12T08:34:34.349559+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
2017-02-12T08:34:34.349573+00:00 app[web.1]: 	from bin/rails:4:in `require'
2017-02-12T08:34:34.349575+00:00 app[web.1]: 	from bin/rails:4:in `<main>'
2017-02-12T08:34:34.480354+00:00 heroku[web.1]: Process exited with status 1
2017-02-12T08:34:34.517204+00:00 heroku[web.1]: State changed from starting to crashed
2017-02-12T08:36:17.649848+00:00 app[api]: Starting process with command `rails db:migrate` by user hironorisama@gmail.com
2017-02-12T08:36:20.419012+00:00 heroku[run.9646]: Awaiting client
2017-02-12T08:36:20.450259+00:00 heroku[run.9646]: Starting process with command `rails db:migrate`
2017-02-12T08:36:20.616017+00:00 heroku[run.9646]: State changed from starting to up
2017-02-12T08:36:27.250323+00:00 heroku[run.9646]: Process exited with status 0
2017-02-12T08:36:27.277640+00:00 heroku[run.9646]: State changed from up to complete
2017-02-12T08:37:20.686532+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=agile-spire-77692.herokuapp.com request_id=cc3e6e04-01ad-46b8-811a-1247f0f54e07 fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
2017-02-12T08:37:22.823068+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=agile-spire-77692.herokuapp.com request_id=8ea87fe0-8821-432c-8475-47257cedb33f fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
2017-02-12T08:39:02.192640+00:00 heroku[slug-compiler]: Slug compilation started
2017-02-12T08:39:02.192672+00:00 heroku[slug-compiler]: Slug compilation finished
2017-02-12T08:39:02.079736+00:00 app[api]: Release v7 created by user hironorisama@gmail.com
2017-02-12T08:39:02.079736+00:00 app[api]: Deploy 3de559b by user hironorisama@gmail.com
2017-02-12T08:39:02.281115+00:00 app[api]: Release v7 created by user hironorisama@gmail.com
2017-02-12T08:39:02.317230+00:00 heroku[web.1]: State changed from crashed to starting
2017-02-12T08:39:04.973217+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 8026 -e production`
2017-02-12T08:39:09.239995+00:00 app[web.1]: => Booting Puma
2017-02-12T08:39:09.240027+00:00 app[web.1]: => Rails 5.0.0.1 application starting in production on http://0.0.0.0:8026
2017-02-12T08:39:09.240029+00:00 app[web.1]: => Run `rails server -h` for more startup options
2017-02-12T08:39:09.851691+00:00 app[web.1]: Exiting
2017-02-12T08:39:09.851789+00:00 app[web.1]: /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require': No such file to load -- pry (LoadError)
2017-02-12T08:39:09.851794+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `block in require'
2017-02-12T08:39:09.851797+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
2017-02-12T08:39:09.851799+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
2017-02-12T08:39:09.851801+00:00 app[web.1]: 	from /app/app/controllers/users_controller.rb:1:in `<top (required)>'
2017-02-12T08:39:09.851804+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
2017-02-12T08:39:09.851805+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `block in require'
2017-02-12T08:39:09.851807+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
2017-02-12T08:39:09.851809+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
2017-02-12T08:39:09.851812+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:380:in `block in require_or_load'
2017-02-12T08:39:09.851814+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:37:in `block in load_interlock'
2017-02-12T08:39:09.851817+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies/interlock.rb:12:in `block in loading'
2017-02-12T08:39:09.851819+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/concurrency/share_lock.rb:117:in `exclusive'
2017-02-12T08:39:09.851821+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies/interlock.rb:11:in `loading'
2017-02-12T08:39:09.851823+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:37:in `load_interlock'
2017-02-12T08:39:09.851825+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:358:in `require_or_load'
2017-02-12T08:39:09.851845+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:336:in `depend_on'
2017-02-12T08:39:09.851847+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:252:in `require_dependency'
2017-02-12T08:39:09.851850+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:476:in `block (2 levels) in eager_load!'
2017-02-12T08:39:09.851850+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:475:in `each'
2017-02-12T08:39:09.851869+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:475:in `block in eager_load!'
2017-02-12T08:39:09.851871+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:473:in `each'
2017-02-12T08:39:09.851888+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:473:in `eager_load!'
2017-02-12T08:39:09.851889+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:354:in `eager_load!'
2017-02-12T08:39:09.851890+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application/finisher.rb:59:in `each'
2017-02-12T08:39:09.851890+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application/finisher.rb:59:in `block in <module:Finisher>'
2017-02-12T08:39:09.851891+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:30:in `instance_exec'
2017-02-12T08:39:09.851892+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:30:in `run'
2017-02-12T08:39:09.851896+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
2017-02-12T08:39:09.851897+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:429:in `each_strongly_connected_component_from'
2017-02-12T08:39:09.851893+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:55:in `block in run_initializers'
2017-02-12T08:39:09.851893+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:226:in `block in tsort_each'
2017-02-12T08:39:09.851898+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:347:in `block in each_strongly_connected_component'
2017-02-12T08:39:09.851899+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `each'
2017-02-12T08:39:09.851901+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `call'
2017-02-12T08:39:09.851902+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `each_strongly_connected_component'
2017-02-12T08:39:09.851904+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:224:in `tsort_each'
2017-02-12T08:39:09.851905+00:00 app[web.1]: 	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:203:in `tsort_each'
2017-02-12T08:39:09.851907+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:54:in `run_initializers'
2017-02-12T08:39:09.851909+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application.rb:352:in `initialize!'
2017-02-12T08:39:09.851911+00:00 app[web.1]: 	from /app/config/environment.rb:5:in `<top (required)>'
2017-02-12T08:39:09.851927+00:00 app[web.1]: 	from /app/config.ru:3:in `require_relative'
2017-02-12T08:39:09.851928+00:00 app[web.1]: 	from /app/config.ru:3:in `block in <main>'
2017-02-12T08:39:09.851934+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/builder.rb:55:in `instance_eval'
2017-02-12T08:39:09.851935+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/builder.rb:55:in `initialize'
2017-02-12T08:39:09.851938+00:00 app[web.1]: 	from /app/config.ru:in `new'
2017-02-12T08:39:09.851939+00:00 app[web.1]: 	from /app/config.ru:in `<main>'
2017-02-12T08:39:09.851941+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/builder.rb:49:in `eval'
2017-02-12T08:39:09.851961+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/builder.rb:49:in `new_from_string'
2017-02-12T08:39:09.851962+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/builder.rb:40:in `parse_file'
2017-02-12T08:39:09.851965+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:318:in `build_app_and_options_from_config'
2017-02-12T08:39:09.851966+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:218:in `app'
2017-02-12T08:39:09.851967+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/server.rb:59:in `app'
2017-02-12T08:39:09.851969+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:353:in `wrapped_app'
2017-02-12T08:39:09.851970+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/rack-2.0.1/lib/rack/server.rb:282:in `start'
2017-02-12T08:39:09.851971+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/server.rb:79:in `start'
2017-02-12T08:39:09.851990+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
2017-02-12T08:39:09.851992+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
2017-02-12T08:39:09.851995+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
2017-02-12T08:39:09.851996+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
2017-02-12T08:39:09.851996+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
2017-02-12T08:39:09.851999+00:00 app[web.1]: 	from bin/rails:4:in `require'
2017-02-12T08:39:09.852001+00:00 app[web.1]: 	from bin/rails:4:in `<main>'
2017-02-12T08:39:10.010562+00:00 heroku[web.1]: Process exited with status 1
2017-02-12T08:39:10.036627+00:00 heroku[web.1]: State changed from starting to crashed
2017-02-12T08:39:21.743457+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=agile-spire-77692.herokuapp.com request_id=6961b72b-e866-4f04-b2bc-c26b03d21b0c fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
2017-02-12T08:39:23.777362+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=agile-spire-77692.herokuapp.com request_id=85e01fea-5b3a-441f-9c74-9035df3993e5 fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
2017-02-12T08:41:07.517027+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=agile-spire-77692.herokuapp.com request_id=e5d0676f-ff78-4e3d-a07f-16e4a184f0d3 fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
2017-02-12T08:41:09.356112+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=agile-spire-77692.herokuapp.com request_id=74d2ac3a-c9f4-46dd-9b0b-d56674d84e6a fwd="24.130.122.7" dyno= connect= service= status=503 bytes=
```

これといって役に立ちそうなことが見つからない。わかったことはエラーの分類が`H10`。<a href="https://devcenter.heroku.com/articles/error-codes#h10-app-crashed" target="_blank">Heroku dev</a>によるとこれはapp-crashとのこと。

##`heroku run rails console`を打ってみる
<a href="http://stackoverflow.com/a/24113266/5922520" target="_blank">SOF</a>を参考にHeroku経由でコンソールを開いてみるとより詳しくエラーを分析できるらしいとのことなのでやってみる。

```
Running rails console on ⬢ agile-spire-77692... up, run.8850 (Free)
/app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require': No such file to load -- pry (LoadError)
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `block in require'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
	from /app/app/controllers/users_controller.rb:1:in `<top (required)>'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `block in require'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:293:in `require'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:380:in `block in require_or_load'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:37:in `block in load_interlock'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies/interlock.rb:12:in `block in loading'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/concurrency/share_lock.rb:117:in `exclusive'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies/interlock.rb:11:in `loading'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:37:in `load_interlock'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:358:in `require_or_load'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:336:in `depend_on'
	from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/dependencies.rb:252:in `require_dependency'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:476:in `block (2 levels) in eager_load!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:475:in `each'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:475:in `block in eager_load!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:473:in `each'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:473:in `eager_load!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/engine.rb:354:in `eager_load!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application/finisher.rb:59:in `each'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application/finisher.rb:59:in `block in <module:Finisher>'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:30:in `instance_exec'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:30:in `run'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:55:in `block in run_initializers'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:226:in `block in tsort_each'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:429:in `each_strongly_connected_component_from'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:347:in `block in each_strongly_connected_component'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `each'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `call'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:345:in `each_strongly_connected_component'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:224:in `tsort_each'
	from /app/vendor/ruby-2.2.6/lib/ruby/2.2.0/tsort.rb:203:in `tsort_each'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/initializable.rb:54:in `run_initializers'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application.rb:352:in `initialize!'
	from /app/config/environment.rb:5:in `<top (required)>'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application.rb:328:in `require'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/application.rb:328:in `require_environment!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:157:in `require_application_and_environment!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:77:in `console'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
	from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
	from /app/bin/rails:4:in `require'
	from /app/bin/rails:4:in `<main>'
```

これはどうやら`pry`がないと嘆いているとのこと。あっそういえば。。。

```Gemfile
source 'https://rubygems.org'


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '5.0.0.1'
# Use Puma as the app server
gem 'puma', '3.4.0'
# Use SCSS for stylesheets
gem 'sass-rails', '5.0.6'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '3.0.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '4.2.1'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails', '4.1.1'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '5.0.1'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '2.4.1'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', '9.0.0', platform: :mri
  # Use sqlite3 as the database for Active Record
  gem 'sqlite3', '1.3.11'
  gem 'pry-rails' #テスト環境にしかいれてなかった。。。。。

end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
  gem 'web-console', '3.1.1'
  gem 'listen', '3.0.8'
  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring', '1.7.2'
  gem 'spring-watcher-listen', '2.0.0'
end

group :production do
  gem 'pg', '0.18.4'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
```
`pry`をテスト環境にしかいれてなかったので`bundle install`でも当然の如くインストールされておらず。それにもかかわらずコントロールファイルには`require 'pry'`と書いてあるのでHerokuが「なんだコレしらねえぞ」と怒っていた模様。

ということで`gem 'pry'`をテスト環境から取り出して`bundle install`あとはgitの手順に従ってHerokuへデプロイ。解決！