Use PostgreSQL 9.3 on Travis CI
Heroku's default is Postgres 9.3 [1], but Travis' default is Postgres 9.1 [2]

[1]: https://devcenter.heroku.com/articles/heroku-postgresql#version-support
[2]: http://docs.travis-ci.com/user/using-postgresql/
Add a `dev:prime` default Rake task
Add `bin/deploy` script
* Help avoid forgetting to run `rake db:migrate`.
* Help avoid forgetting to run `restart` after migrate.
* Use the shebang line for POSIX sh.
* Default the argument to 'staging'