Add bourbon

:warning: WIP do not merge :warning: 

This is a proposal to add bourbon and his family as default on pah. This way when I start a app and add a simple html I already have a good default to start like this.

![captura de tela 2014-06-27 as 17 56 02](https://cloud.githubusercontent.com/assets/260746/3417813/879d5370-fe3d-11e3-8079-e38159961c53.png)

And all the others styles defined by bitters as you [can see here](http://bitters.bourbon.io/images/bitters-example.jpg).

A by product by bitters is the good practice of creating css files, since his organization is pretty cool. I talk more about [bourbon and his family here](http://helabs.com.br/blog/2014/06/27/rails-front-end-com-bourbon-e-sua-familia/).

cc/ @mergulhao @TiuTalk @Helabs/designers