#5 Move completely from unittest to pytest.

[Anu9518]

type: Refactor
subject: Chang unittest to pytest

[nikochiko]

I'm not sure why Travis isn't running on this PR. But anyway, what I had in mind was tests like these -> https://github.com/nikochiko/df-wizard-chess/blob/master/tests/test_utils.py#L63-L85 (the whole file). When we use unittest, and subclass our test classes to unittest.TestCase, we're allowed to have a setup class, a tear down class and self.assertEqual or self.assert{some_condition}. The format is a bit different with pytest, and since we don't subclass it to any other classes, we have to use python's inbuilt assert statements. You can refer this -> https://www.jitsejan.com/moving-from-unittest-to-pytest.html