Pull request for Lecture 2 assignments for sea-c28

This is a really cool use of *args!

Using Python's implied line continuation inside parenthesis is a great (and correct) way to wrap long lines. However, I find that assigning intermediate symbols makes the code more readable when there are operators or comparisons (such as ==) in the long line. Something like this:

    for n in range(2):
        test_output = sum_series(*test_values_sum_series[n][0:3])
        expected = test_values_sum_series[n][3]
        assert test_output == expected

This, of course, is purely stylistic preference.