Session02

Jesse Klein's Ackermann's function module
Series module added as well
This `assert` statement is asserting that the tuple that contains the listed function evaluates to True. This statement will always be True as long as those functions are defined. 

Instead, we want to use `assert` to do some basic unit testing to prove that our functions work as expected. The basic structure should be something like this:

    if __name__ == "__main__":
        # assert function(input) == expected
        # ...
        assert fibonacci(7) == 13
        # ...
        assert lucas(4) == 7
        # ...
        assert sum_series(4, 2, 1) == lucas(4)
        # ...
        print('all tests passed!')

The above code isn't ideal though as it can be improved to reduce repetition.

Also, consider alerting the user to the outcome of these tests. If I had ran your file without reading the code I wouldn't know that these assertions existed.