updating version to 1.5.1 to match ambari-server
updating version to 1.5.1 to match ambari-server

dlyle65535/ambari-rest-client,jagatsingh/ambari-rest-client,sequenceiq/ambari-rest-client,sequenceiq/ambari-rest-client,jagatsingh/ambari-rest-client,dlyle65535/ambari-rest-client