We add the flake8 configuration used so we ensure everyone uses the same.
We remove the usage of __all__ for non public API.
When possible, we rationalize the class name according to its __name__ and module.
issue9082
review297061002
distutils import tests module from the source code, so we must force it to use
the test suite from the absolute path because it will be the converted on in
case of 2to3 otherwise we fall-back to the relative module.
issue3211
Cédric Krier