Add missing workaround
Add missing workaround

This workaround was missing and is needed to run tests on ruby 2.0.

quartzmo/google-cloud-ruby,quartzmo/google-cloud-ruby,googleapis/google-cloud-ruby,landrito/google-cloud-ruby,googleapis/google-cloud-ruby,landrito/google-cloud-ruby,CloudVLab/google-cloud-ruby,googleapis/google-cloud-ruby,CloudVLab/google-cloud-ruby,dazuma/google-cloud-ruby,landrito/google-cloud-ruby,landrito/google-cloud-ruby,dazuma/google-cloud-ruby,landrito/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,blowmage/gcloud-ruby,CloudVLab/google-cloud-ruby,CloudVLab/google-cloud-ruby,quartzmo/google-cloud-ruby,quartzmo/google-cloud-ruby,googleapis/google-cloud-ruby,quartzmo/google-cloud-ruby,quartzmo/gcloud-ruby,CloudVLab/google-cloud-ruby,dazuma/google-cloud-ruby,dazuma/google-cloud-ruby,quartzmo/google-cloud-ruby,dazuma/google-cloud-ruby