Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Alex Suraci:
     Use larger quotas when staging apps with Diego ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/29465051 )
     Avoid referring to git in buildpack url ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/29463172 )
     Accept buildpack URLs that do not end in .zip for Diego ( Travis Unknown )
     Make spec folders mirror source ( Travis Unknown )
     Rename GitBasedBuildpack to CustomBuildpack ( Travis Unknown )

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