workaround for bug with Storm's LocalCluster not getting cleaned up prop...

Tom -  Thanks for your excellent work on this library. We are going to use it on our current project. We want to write more tests to verify our changes, but as you know the Storm issue prevents the build from passing.  This change set  works around that issue by executing each of the  test methods in this main test class within a different JVM. 

This isn't ideal since the tests take longer and you only get a report of the last test run, but at least the build will only fail if something is really wrong now.  Hope you find the change to be useful.
 - chris