Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  James Myers:
     Merge branch master of https://github.com/cloudfoundry/cloud_controller_ng ( Travis created: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/27915780 )
     Merge remote-tracking branch origin/pr/254 ( Travis Unknown )
  Zach Robinson:
     minor readability refactor ( Travis Unknown )
  Eric Malm:
     Change app security group rules to consume JSON ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/27915287 )
  Joseph Palermo:
     Use match_array to fix flakey array comparison ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/27913932 )
  Srini Brahmaroutu:
     Do not allow private domains that overlap with shared domains ( Travis Unknown )

Signed-off-by: James Myers <jmyers@pivotallabs.com>