Merge branch 'rs-fuubar' into 'master'

Add Fuubar as the default RSpec formatter

- Shows how many specs have been run, how many remaining
- Estimates how long is left
- Instantly shows failures
- Looks awesome 

![Screen_Shot_2015-06-26_at_1.00.47_AM](https://gitlab.com/gitlab-org/gitlab-ce/uploads/da7c989e04237141d9adb4c4b5898359/Screen_Shot_2015-06-26_at_1.00.47_AM.png)

See merge request !893