Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Phan Le and Tim Labeeuw:
     Change Sham.guid to be a unique UUID. Fixed the loggregator test pollution. Fixed app staging integration spec test pollution. ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12956980 )
  Matt Royal and Ryan Tang:
     Log requests to and responses from v2 brokers ( Travis finished: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12956441 )
  David Stevenson and Matt Royal:
     V2 Broker API passes addtnl fields to deprovision ( Travis Unknown )
     V2 Broker API passes additional fields in unbind ( Travis Unknown )
     V2 Broker API passes additional fields in binding ( Travis Unknown )
     V2 Broker API passes additionl fields in provision ( Travis Unknown )
  Ruth Byers and Tim Labeeuw:
     All rspec processes shared the same seed ( Travis finished: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12945557 )
     Create the stacks only needed ( Travis Unknown )
     Order the CC test randomly on travis ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12941397 )
     Must always have non_transactional if your trying to test an after_commit hook ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12907628 )
  Jeff Schnitzer and alex choi:
     syslog_drain_url is an optional field in service broker responses ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12910327 )
     Make credentials and syslog_drain_url optional. ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12908855 )