Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Onsi Fakhouri:
     Diego stager task disallows .git buildpacks ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/23145564 )
Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Alex Stupakov and Zach Robinson:
     Return "Invalid Auth Token" description when token does not contain cloud_controller.read scope ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/23146753 )