Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Cornelia Davis and Jeff Schnitzer:
     v2 service brokers now auth with username/password rather than a token. ( Travis Failed: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12116711 )
  Maria Shaldibina and Onsi Fakhouri:
     Add noop option for HM9000 ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12115443 )
  Julz Friedman and Ruth Byers:
     Added app API spec ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/12114096 )
     send buildpack_key or buildpack_git_url in staging message ( Travis Unknown )
  Julz Friedman and Phan Le:
     Remove ActiveRecord db setup ( Travis Unknown )
     Unpending test ( Travis Unknown )
     Fail with more information for debugging ( Travis Unknown )
     Ignore the generated doc folder ( Travis Unknown )
  Phan Le and Ruth Byers:
     Set the buildpack url as custom buildpack if the user uses --buildpack ( Travis Unknown )