fix unit tests by defaulting to threading.RLock
fix unit tests by defaulting to threading.RLock

benauthor/pykafka,wikimedia/operations-debs-python-pykafka,benauthor/pykafka,thedrow/samsa,benauthor/pykafka,thedrow/samsa,wikimedia/operations-debs-python-pykafka,thedrow/samsa,wikimedia/operations-debs-python-pykafka