Bump src/acceptance-tests, src/cloud_controller_ng

Bump :
  Chris Piraino, Luan Santos and Rick Reilly:
     Add CATS test for /v2/apps/:guid/copy_bits endpoint.
  Alex Stupakov:
     Add test for loggregator firehose [#80870620]
Bump cloudfoundry/cloud_controller_ng:
  Eric Malm and James Myers:
     Merge remote-tracking branch origin/wip-81201540 ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/39210027 )
     Update rspec gem ( Travis Unknown )
     /v2/apps/:guid/copy_bits is always async ( Travis Unknown )
  Matthew Sykes:
     Add index to worker name ( Travis Success: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/38863794 )
Bump src/cloud_controller_ng

Bump cloudfoundry/cloud_controller_ng:
  Chris Piraino and Serguei Filimonov:
     Avoid time zone and DST-related bugs by switching to Time.current. ( Travis started: https://travis-ci.org/cloudfoundry/cloud_controller_ng/builds/39211623 )