branch.py: ensure we're tracking skins/* changes
We remove the *
from mediawiki/core's extensions/.gitignore
as part
of branching.
Currently, we do not remove the /*
from mediawiki/core's
skins/.gitignore
.
This makes the two consistent with one another and ensures we see local
modifications for both directories on the deploy host.
Refactors to a single implementation that looks for both '' and '/'
and adds a handful of test cases.