I'd prefer to have this test suite extend [LocalSparkContext](https://github.com/apache/incubator-spark/blob/master/core/src/test/scala/org/apache/spark/LocalSparkContext.scala) and rely on that to perform the cleanup and Akka port clearing (here's an example of this FileSuite: https://github.com/apache/incubator-spark/blob/master/core/src/test/scala/org/apache/spark/FileSuite.scala#L32)