Remove `foreman` from Gemfile

https://github.com/ddollar/foreman/pull/437#issuecomment-41110407
Use `<%=` for `app_name` in `newrelic.yml` instead of `<%`

:disappointed:
Update sample .env [ci skip]
Add unicorn
Setup `config/unicorn.rb`

Use `dotenv` gem to read `.env` file and update it when the server
starts or restarts. Configure number of unicorn workers via `ENV`
variable.
Add unicorn deploy tasks
Setup `capistrano-env` for managing ENV variables
Use unicorn web server in production [ci skip]

* Setup deploy tasks for capistrano using `capistrano-unicorn` gem
* Manage `.env` file on production using `capistrano-env` (via
  ecbypi/capistrano-env on GitHub)
Add `PtsMembership` command

Shells out to `pts` command line utility for checking members of
specified AFS group. Handles when command has a 0 exit status but
returns an error message.
Add worker to sync users that have the desk worker role

Runs every 5 minutes. Notifies `Honeybadger` if
`ENV['DESK_WORKERS_GROUP']` is missing or if the command failed.
Extract meaningful methods in SyncRolesWorker