If the has_image|has_container evals to True, then return
the proper object; else None
Add unittest structure for backends/backendutils.py
We want to make sure we have a good backend/backendutils
unittest. This should simplify unittests for all backends.
refactor.py: Remove the file used to help mini-test the
refactoring work. It is not needed by upstream and was
only including during the development phases.
Closes: #757
Approved by: baude
Atomic/backendutils.py: Class for working with unknown backend
Atomic/objects/image|layer|container.py: classes for objects
Atomic/backends/backend|_docker|_ostree.py: Abstract backends for ostree and docker
Closes: #757
Approved by: baude
