[API] Add HBase decommission command.
[API] Add HBase decommission command.

cloudera/cm_api,cdapio/cm_api,cloudera/cm_api,cloudera/cm_api,cdapio/cm_api,cdapio/cm_api,justinhayes/cm_api,justinhayes/cm_api,justinhayes/cm_api,cdapio/cm_api