When using the argument "all" in our pylint
script, we invoke tests against the whole tree.
This doesn't really work well with module names
since it ignores some submodules that are not
traversable from the main manila module.
By using filenames, we allow pylint to cover
all modules.
Change-Id: I37ea7f72e71ae93f8f654e0aa99744b2ecc1cea9