ref #987 - Support for phantomjs v2.x

Hi,
We were in desperate need to test websocket (xSockets v4) functionality in the app were developing. For this we had to upgrade to the very new (unstable) release of phantomjs 2.0. Currently casperjs didn't allow us to start this new version.
I have edited the bootstrap.js to allow phantomjs of version 2.x.

I hope i have done it correctly (my first PR), any feedback is appreciated.