devel/py-unittest2pytest: add port: Convert unittest test-cases to pytest

unittest2pytest is a tool that helps rewriting Python unittest
test-cases into pytest test-cases.

In contrast to other similar tools, this unittest2pytest

• handles keyword arguments,
• handles single-line test-cases and several tests on one line,
• uses context-handlers where appropriate.

This is done by using lib2to3 and Python's mighty inspect module.

WWW: https://pypi.org/project/unittest2pytest/
WWW: https://github.com/pytest-dev/unittest2pytest