Remove unittest2 import
Remove unittest2 import

Patch by Jeff Widman; reviewed by brandonwilliams for CASSANDRA-16506

michaelsembwever/cassandra,szhou1234/cassandra,belliottsmith/cassandra,mike-tr-adamson/cassandra,tjake/cassandra,michaelsembwever/cassandra,tjake/cassandra,thelastpickle/cassandra,tjake/cassandra,apache/cassandra,adelapena/cassandra,adelapena/cassandra,apache/cassandra,pauloricardomg/cassandra,instaclustr/cassandra,driftx/cassandra,mshuler/cassandra,thelastpickle/cassandra,jrwest/cassandra,mike-tr-adamson/cassandra,pauloricardomg/cassandra,driftx/cassandra,szhou1234/cassandra,belliottsmith/cassandra,szhou1234/cassandra,instaclustr/cassandra,driftx/cassandra,michaelsembwever/cassandra,tjake/cassandra,apache/cassandra,driftx/cassandra,pauloricardomg/cassandra,mshuler/cassandra,michaelsembwever/cassandra,jrwest/cassandra,instaclustr/cassandra,mike-tr-adamson/cassandra,blambov/cassandra,belliottsmith/cassandra,mshuler/cassandra,blambov/cassandra,pauloricardomg/cassandra,mshuler/cassandra,thelastpickle/cassandra,belliottsmith/cassandra,szhou1234/cassandra,instaclustr/cassandra,jrwest/cassandra,thelastpickle/cassandra,blambov/cassandra,mike-tr-adamson/cassandra,adelapena/cassandra,blambov/cassandra,apache/cassandra,adelapena/cassandra,jrwest/cassandra