Devise setup done

@carolineartz @gpuglia  @mhamel01 I pulled from the development branch, then added/configured the Devise gem. Users can sign in/sign up now.

![screen shot 2014-06-06 at 9 29 09 pm](https://cloud.githubusercontent.com/assets/632721/3207548/92c7bcb6-edeb-11e3-8423-8899b71364a8.png)

My concern is that I see sqlite files under /db. Didn't Mike delete those yesterday?