Password reset

Add ability for users to reset their passwords via email. Also allows users to edit their email and passwords within the app. Resolves #13 .
It'd be great if this read `/config/*.yml` with example `yml` files provided so that another dev can easily configure things to their environment.

See [Github's gitignore](https://github.com/github/gitignore/blob/master/Rails.gitignore) project for other things you might want to add here.