This container can be pulled via:
  docker pull registry.opensuse.org/home/dcassany/fix_chart/containerkiwi/suse/sl-micro/6.1/toolbox:16.3
  docker pull registry.opensuse.org/home/dcassany/fix_chart/containerkiwi/suse/sl-micro/6.1/toolbox:16.3-1.56
  docker pull registry.opensuse.org/home/dcassany/fix_chart/containerkiwi/suse/sl-micro/6.1/toolbox:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.