This container can be pulled via:
  docker pull registry.opensuse.org/home/tbechtold/openstack-containers/opensuse_leap_15.1/images/opensuse/memcached:1.5.6
  docker pull registry.opensuse.org/home/tbechtold/openstack-containers/opensuse_leap_15.1/images/opensuse/memcached:1.5.6-2.1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.