public MiniZooKeeperCluster startMiniZKCluster(int zooKeeperServerNum, int... clientPortList)
    throws Exception {
    setupClusterTestDir();
    return startMiniZKCluster(clusterTestDir, zooKeeperServerNum, clientPortList);
  }
Call this if you only want a zk cluster.
@see #shutdownMiniZKCluster()
@return zk cluster started.
hbase-zookeeper/src/test/java/org/apache/hadoop/hbase/HBaseZKTestingUtil.java