test radosgw with command line interface

added swift-based tests for radosgw
You can do anything in https://github.com/jsuchome/automation/blob/radosgw_tests/scripts/qa_crowbarsetup.sh#L886

And I think the controller node is getting the radosgw role anyway, isn't it? See https://github.com/crowbar/barclamp-ceph/blob/master/crowbar_framework/app/models/ceph_service.rb#L104 So it should be correct by default.