Merels was ported to game_handler recently, but it's tests were not revised. They need to be reworked. Tests for connect_four bot can serve as good examples for how to modify the tests for Merels.

merels.py was totally changed so write new set of tests for it. Files in libraries were not much changed so they need to be tweaked to accomodate for the changes.

Enable testing for merels by adding __init__.py file to the directory.