Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  James Myers:
     Update yajl-ruby to 1.2.1 ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/26901777 )
  Abhijit Hiremagalur:
     Remove ModelExamples module as it does not actually scope the shared examples ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/26899829 )
     Remove ControllerExamples module as it does not actually scope the shared examples ( Travis Unknown )
     Remove controller specs which are testing model behavior ( Travis Unknown )
  Zach Robinson:
     add timeout to tps call in diego_client ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/26897288 )

Signed-off-by: Sabha Parameswaran <sparameswaran@gopivotal.com>