Use grunt-karma and grunt-simple-mocha for running all tests.

As promised the conversion to using karma. 

Tasks left to do

- [x] Make all tests pass again
- [x] Configure Travis to use Firefox
- [ ] Make Travis work: [![Build Status](https://travis-ci.org/Dignifiedquire/ShareJS.png?branch=integration_test)](https://travis-ci.org/Dignifiedquire/ShareJS)