Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Zach Robinson:
     Move broker api spec helpers to their own file [finishes #62436340] ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16565495 )
  Jimmy Da and Zach Robinson:
     Move service broker api tests [finishes #63344456] ( Travis Unknown )
     Add checksum testing to prevent accidental changes to compatibility tests [finishes #63344256] ( Travis Unknown )
     Revert "Replace before(:all) hooks with before(:each) in unit tests" ( Travis Unknown )
  Jimmy Da:
     Revert "reverting error message related commits which broke build" ( Travis Unknown )
  Maria Shaldibina:
     Fix test to check parameter attributes ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16497355 )
     Emit loggregator message on app exit ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16481451 )
     Move loggregator emit message on app delete to AppEventRepository ( Travis Unknown )
     Move loggregator emit message on app create to AppEventRepository ( Travis Unknown )
     Move app.update loggregator message to AppEventRepository ( Travis Unknown )
     Memoize app_event_repository instance ( Travis Unknown )
  Abhijit Hiremagalur:
     Split AppEventRepository and SpaceEventRepository ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16350300 )
     Inject the EventRepository in apps and spaces controller ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16348064 )
     Fixing tests ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16343875 )
     Inline class methods on Event ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16343167 )
     Extract EventRepository for Event ( Travis Unknown )
  Matt Royal and alex choi:
     reverting error message related commits which broke build ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16328219 )
     Revert "Don't print array literals in error messages" ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16294207 )
     Revert "adding tests for error formatting of errors class" ( Travis Unknown )
     adding tests for error formatting of errors class ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16292611 )
     Don't print array literals in error messages ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16291106 )
  Ruth Byers:
     Replace before(:all) hooks with before(:each) in unit tests ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16327705 )
  Eric Malm:
     Remove loggegrator integration test as it is already covered in a unit test ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16271475 )
     Fix flaky loggregator integration spec ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16271295 )
     Merge pull request #142 from cloudfoundry/only_seed_app_usage_events_with_started_apps ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16153971 )
  phanle:
     Remove unused code ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16230639 )
  Joseph Palermo & Sean Brady:
     Only seed app usage events with STARTED apps. ( Travis finished: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/16150401 )