koji_promote: use better archive name for v1 image
koji_promote: use better archive name for v1 image

Rather than using 'compressed.tar.gz' we should use a fixed prefix
(e.g. 'docker-v1-image-') and append the unique identifier of the
image.

fr34k8/atomic-reactor,maxamillion/atomic-reactor,fr34k8/atomic-reactor,projectatomic/atomic-reactor,jarodwilson/atomic-reactor,jarodwilson/atomic-reactor,projectatomic/atomic-reactor,vrutkovs/atomic-reactor,vrutkovs/atomic-reactor,jpopelka/atomic-reactor,maxamillion/atomic-reactor,DBuildService/atomic-reactor,DBuildService/atomic-reactor,jpopelka/atomic-reactor