Config: Add matrix of _all_ SL/BS options

Just build permutations from several arrays to programmatically create things like:

``` yml
    - ROWDY_SETTINGS="sauceLabs.safari7-mac"
    - ROWDY_SETTINGS="sauceLabs.chrome-win7"
    - ROWDY_SETTINGS="sauceLabs.firefox-win7"
    - ROWDY_SETTINGS="sauceLabs.ie9-win7"
    - ROWDY_SETTINGS="sauceLabs.ie10-win7"
    - ROWDY_SETTINGS="sauceLabs.ie11-win8"
```
