Switch to pytest

[Flamefire]

I'd suggest using pytest for testing. It is much easier to use and offers plugins which can be e.g. used for coverage analysis.

Examples:

• no more if __name__ == '__main__': unittest.main(), just name functions test_*
• self.assertEqual -> assert foo==bar
• pytest --cov=coverageFolder --cov-fail-under=90

Note that it does not require to rewrite all tests at once, pytest works with unittest tests. But for new tests the easier syntax can be used.