test: Separate stop and publish commands in test_clustering_image_replication
test: Separate stop and publish commands in test_clustering_image_replication

For readability and clarity over which one fails if they fail.

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

hallyn/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,atxwebs/lxd,stgraber/lxd