Merge branch 'git_hook-file_pattern_match' into 'master'

Git hook file pattern match

I found that with the git hook installed, flake8 was failing to check some files. Upon examination, I found that the hook is coded to only consider files ending in '.py'. This works out to be an override of the expected behavior, which is to honor the "filename" option in tox.ini.

See merge request !1