Update cloudbuild.yaml (#82)
Update cloudbuild.yaml (#82)

1.18 has broken this sample.  Pinning to 1.17.
GoogleCloudPlatform/cloud-build-samples,GoogleCloudPlatform/cloud-build-samples,GoogleCloudPlatform/cloud-build-samples,GoogleCloudPlatform/cloud-build-samples,GoogleCloudPlatform/cloud-build-samples,GoogleCloudPlatform/cloud-build-samples