Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Abhijit Hiremagalur:
     CC fails to stage if app wants Diego and Diego is disabled ( Travis Unknown )
     InstancesReporter is Diego based if app wants it ( Travis Unknown )
     Centralize knowledge of Diego env vars ( Travis Unknown )
     Make diego client send_stage_request match docker client ( Travis Unknown )
     Introduce Diego::Docker::Client ( Travis Unknown )

Signed-off-by: Stewart Nickolas <nickolas@us.ibm.com>