fix TestPartitionOwnerRegistry by waiting for zk to coalesce.
fix TestPartitionOwnerRegistry by waiting for zk to coalesce.

aeroevan/pykafka,thedrow/samsa,vortec/pykafka,sontek/pykafka,yungchin/pykafka,aeroevan/pykafka,jofusa/pykafka,benauthor/pykafka,appsoma/pykafka,thedrow/samsa,thedrow/samsa,wikimedia/operations-debs-python-pykafka,fortime/pykafka,sontek/pykafka,fortime/pykafka,benauthor/pykafka,wikimedia/operations-debs-python-pykafka,sammerry/pykafka,vortec/pykafka,benauthor/pykafka,appsoma/pykafka,sammerry/pykafka,tempbottle/pykafka,jofusa/pykafka,yungchin/pykafka,wikimedia/operations-debs-python-pykafka,tempbottle/pykafka