Installed gems and configuration for Heroku Cedar.

Cedar doesn't automatically add these to our app like Bamboo did.

Conflicts:
	Gemfile
	Gemfile.lock
Set up Procfile for Heroku process management.

.env contains environment variables to simulate a Heroku environment in
development. It should not be checked in (because it's for dev only).
Disabled the asset pipeline on Cedar.

We weren't actually using it, but on Cedar we got error messages when
precompilation failed. Disabling in the hope that we won't get error
messages.
Maybe fix "no such middleware" error on Heroku.

Heroku couldn't find ActionDispatch::Static when precompiling assets,
because AD::S is only included if serve_static_assets is true. According
to someone on Stack Overflow, Heroku overrides this configuration
anyway, so we might as well turn it on and avert the error.

http://stackoverflow.com/questions/7824570/heroku-conflict-between-gzipping-assets-and-precompiling-assets
Try again to prevent precompile error on Heroku.

Heroku says it won't try to precompile assets if there's already a
manifest file, so I made one.
Merge branch 'cedar-no-pipeline'

We're live on Cedar.