Explicit host:localhost required on Ubuntu
Added a PullRequest model
Ditching Vagrant for AWS

Vagrant is cool, but paying for a server that can run a decent-sized vm but not using
that capacity most of the time is pretty pointless. Spinning up an AWS instance on
demand makes much more sense. Updated readme to reflect that shift in planned architecture.

Also added an application.yml.example to stand in for the one that's gitignored
secret_token.rb can be in here, it contains nothing secret