Good for testing! Probably should be restructured to be more object oriented!
.. automodule:: test_wordmake :members:
.. testsetup:: * import wordmake
>>> wordmake(['a', 'b', 'c', 'd'], 2)
['aa', 'ab', 'ac', 'ad', 'ba', 'bb', 'bc', 'bd', 'ca', 'cb', 'cc', 'cd', 'da', 'db', 'dc', 'dd']