Initial Rails stack setup for Heroku

Blank Rails app with a welcome controller:

https://signupsumo-web.herokuapp.com

![Screenshot](http://cl.ly/image/150T2f173J1d/Screen%20Shot%202014-12-19%20at%2020.06.30.png)

Comes with:

  * bootstrap
  * slim
  * rspec
  * meta_tags