tests: run doctests via pytest pytest can run doctests as part of the standard testsuite run. See documentation at [1]. pytest will discover doctests in all python files it can find. However, some files cannot be imported directly in this manner. Fix this by adding a filter in conftest.py in the root directory. This code could also live in kallithea/conftest.py, but it cannot be in kallithea/tests/conftest.py because that level is deeper than the files we want to filter. [1] https://docs.pytest.org/en/latest/doctest.html