Use an up-to-date manifest from the upstream osbuild CI test data
and also specify an output directory, so that osbuild is actually
attempting to produce an image.
Add a simple smoke test that currently just executes osbuild with
the '--help' option to check that it can run at all.
Gate for rawhide (via bodhi_update_push_stable) and for stable
(via bodhi_update_push_testing) on a minimum of dist checks as
well as the smoke test above.
