WTF Ruby

Things I should've known.


Using `UserDict` in Py2 and Py3
How to use `UserDict` in Python 2 and 3
Partial indices can be a bad idea
Why you shouldn't use partial indices
Fake `open` with Python doubles
How to test `open` with the doubles library
Uber's Python test doubles are awesome
Use doubles instead of mock
Bust github badges cache
How to bust a cached badge on github