Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Eric Malm and James Myers:
     Merge remote-tracking branch origin/pr/273 ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/30496895 )
  pivotal:
     rename loggregator_endpoint to metron_endpoint ( Travis Unknown )