Fix to FuncUnit for phantomjs to exit cleanly

See issue:  http://forum.javascriptmvc.com/topic/phantomjs-doesn-t-exit-cleanly-monkey-patched

Submitting fix, as we were having an issue with PhantomJS not exiting properly.
Merge pull request #114 from hartjus/patch-1

Fix to FuncUnit for phantomjs to exit cleanly