Recursively flattens a list of any depth. Made just to check pypi and travis ;)
Recursively flattens list containing nested ones.
[1, [2, [3, [4, ]]]]
will get flatten to:
[1, 2, 3, 4, 5]
I made that just for learning purposes and check out the process of publishing package on pypi, and learn something abou Travis.