Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Summer Zhao and Zach Robinson:
     Bump broker api to 2.2 [#68129608] ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/21611531 )
  Eric Malm:
     Merge remote-tracking branch 'origin/pr/177' ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/21610061 )
  Alex Stupakov and Derek Richard:
     fix whitespace to appease the rubocop ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/21555416 )
     Prevent CC from creating orphaned clients in UAA: ServiceDashboardClients can now exist without an associated broker and can be re-used ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/21553469 )
  Srini Brahmaroutu:
     moving file into the new structure ( Travis Unknown )
     adding Rest Api documentation for space and app summary ( Travis Unknown )
     updating the checksum ( Travis Unknown )