In Fedora Atomic 27 etcd and flanneld are removed from the base image.
Install them as a system containers.
* update docker-storage configuration
* add etcd and flannel tags as labels
Change-Id: I2103c7c3d50f4b68ddc11abff72bc9e3f22839f3
Closes-Bug: #1735381
(cherry picked from commit d95ba4d1ff)