LeetCode 8: String To Integer

We are solving LeetCode 8 "String to Integer (atoi)" because this one also has generated a lot of grief in the reviews (3.3k 👍 vs 10.2k 👎).
A simple greedy algorithm but way too many complains on edge cases.

Solved in Python 3

Blog post here: https://yeah.computer/posts/006-leetcode-8-string-to-int/