update Bootstrap Sass source and relevent tests

Hi,

Updated the bower source for Bootstrap Sass to `bootstrap-sass-official` so it returns the latest build from Bootstrap. Also updated the test suite. Cheers

![screen shot 2014-08-10 at 09 19 54](https://cloud.githubusercontent.com/assets/2131246/3868816/88be2b0c-2067-11e4-9ed2-9c2c1ea1c14e.png)