I want to add RobolectricFragmentTestRunner

Our team have a plan to develop android app using Fragment heavily. So I want a test runner for Fragment test. That's why I want to add "RobolectricFragmentTestRunner"

I referenced DialogFragmentTest.java from robolectric and a [article](http://stackoverflow.com/questions/11333354/how-can-i-test-fragments-with-robolectric/12903280#) wrote by [Corey Leigh Latislaw](https://github.com/colabug).

It will be very helpful if I can use it !!!