Sleep for 500 ms on shutdown to let AMQP connection be closed properly
Sleep for 500 ms on shutdown to let AMQP connection be closed properly

Otherwise RabbitMQ log will be full of warnings

final-ci/travis-worker,ireznice/travis-worker,gavioto/travis-worker,final-ci/travis-worker,ireznice/travis-worker,travis-ci/travis-worker,travis-ci/travis-worker,gavioto/travis-worker