Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Phan Le:
     instrument app staging task ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/18239857 )
     enable gc profiling so that newrelic can collect that information ( Travis Unknown )
  Kris Kelly:
     Bump vcap-common ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/18220258 )
     Add an error to job presenter if job failed ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/18218722 )
  David Varvel and Ruth Byers:
     Flatten out the structure of Diego staging messages. ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/18217122 )

Signed-off-by: Kris Kelly <kkelly@pivotallabs.com>