HBASE-11037 Race condition in TestZKBasedOpenCloseRegion.

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1588609 13f79535-47bb-0310-9956-ffa450edef68
HBASE-11030 HBaseTestingUtility.getMiniHBaseCluster should be able to return null.

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1588616 13f79535-47bb-0310-9956-ffa450edef68