Retry on failure when creating a user profile.
Merge branch 'retry'
Configure sensible timeouts in production

See https://github.com/heroku/rack-timeout
Merge branch 'timeouts'
Add Sequel binstub to run migrations
Switch from SQLite to PostgreSQL
Configure Travis CI to use PostgreSQL
Configure db connections for Unicorn forks
Merge branch 'postgres'
Add error pages

- Uses [Gaffe] to handle exceptions
- Follows [content design from GOV.UK](https://github.com/alphagov/static/tree/master/app/views/root)

[gaffe]: http://open.mirego.com/gaffe/