docs: fix incorrect spanner examples (#2142)
docs: fix incorrect spanner examples (#2142)


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