This container can be pulled via:
  docker pull registry.opensuse.org/home/steven.hardy/branches/isv/metal3/packages/containerfile/suse/cluster-api:1.6.0
  docker pull registry.opensuse.org/home/steven.hardy/branches/isv/metal3/packages/containerfile/suse/cluster-api:1.6.0-bp155.3.59
  docker pull registry.opensuse.org/home/steven.hardy/branches/isv/metal3/packages/containerfile/suse/cluster-api:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.