Update dependencies, refactor to promises, Heroku bootstrap

[brabster]

Hi there,

I used your project in a demo of Heroku Pipelines yesterday, so I've got a version that's got up-to-date resources and a mostly complete refactor to use promises instead of callbacks.

It also uses db-migrate for the database setup and has a couple of setup files that means it'll "just work" with Heroku.

Happy to finish tidying it up and submit a PR if you want it!

[mjhea0]

I think I'd probably write a new blog post for this. Can you submit the PR and I'll figure out how to incorporate it into the new post? Thanks!