RFC for running end-to-end testing of roslibjs. 

I want to get some feedback on the idea of testing roslibjs via rostest. 

Strictly speaking, roslibjs can be used & developed w/o ROS, but it'll be hard to certify that it's working fully. This adds a separate ROS package for integration testing. It contains launch files and js tests to be run in a browser. It could be made into a separate repo or roslibjs itself could be converted to a ROS package. Thoughts?

After that there's a question of using phantomjs v.s. a real browser. phantomjs is nice, but it doesn't support the latest websockets. There're 3 alternatives: fall back to "draft76" for testing (change https://github.com/RobotWebTools/rosbridge_suite/blob/develop/rosbridge_server/src/tornado/websocket.py#L186); use a real browser (e.g. chrome) or try rolling with phantomjs2. I haven't built phantomjs2 yet. 

This branch uses chrome for best compatibility. I verified that changing back to phantomjs and overriding allow_draft76 works as well.