Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Ted Young:
     Internal endpoints use InternalApi auth instead of BulkApi ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/37836213 )
  Matthew Sykes:
     Use http for diego staging responses ( Travis Unknown )

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>