contrib: add nautilus image to docker hub
contrib: add nautilus image to docker hub

The first RCs are out and Nautilus is around the corner, so we can start
building images from the RC.

Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

ceph/ceph-docker,ceph/ceph-docker