In Python3, if there are filenames encoded with 8-bit encodings, there
might be an issues with converting them into unicode objects. This is a
workaround on this subject. Python2 is not affected.
Other than that, there was tests added to cover this case, appropriate
Makefile which automate creating venvs for both: Python 2 and 3, and
also there is a check against pep8 rules using flake8.
