Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Peter Parente:
     Avoid Diego prefix since code is namespaced ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/31290377 )

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>