Don't use `gcloud docker`. (#4245)
Don't use `gcloud docker`. (#4245)

It prints out a big warning about being deprecated when you do this.
ewiseblatt/spinnaker,spinnaker/spinnaker,duftler/spinnaker,ewiseblatt/spinnaker,ewiseblatt/spinnaker,spinnaker/spinnaker,spinnaker/spinnaker,duftler/spinnaker,spinnaker/spinnaker,ewiseblatt/spinnaker,duftler/spinnaker,duftler/spinnaker