Fix of listen_test access issue when calling compass watch

Related to ticket #1497

The way the listener was started, it included the compass gem stylesheet directory, which is read-only for default installs, thus getting the EACCES error. 

Couldn't find any existing unit tests that involved registering a framework.  I did run existing unit tests and verified they still worked.  I also verified that I'm no longer getting the permission issue.

I don't really do ruby.  Please review.