vision: update system tests after breaking change in #2555
vision: update system tests after breaking change in #2555

jgeewax/gcloud-node,googleapis/google-cloud-node,GoogleCloudPlatform/gcloud-node,googleapis/google-cloud-node,googleapis/google-cloud-node,googleapis/google-cloud-node,jgeewax/gcloud-node,GoogleCloudPlatform/gcloud-node,GoogleCloudPlatform/gcloud-node