• Drop support for EOL Python <2.7 and 3.2-3.3
• Check for unused exception binding in except: block
• Handle string literal type annotations
• Ignore redefinitions of _, unless originally defined by import
• Support __class__ without self in Python 3
• Issue an error for raise NotImplemented(...)
• Process function scope variable annotations for used names
• Find Python files without extensions by their shebang

Signed-off-by: Pierre-Yves <pyu@riseup.net>

• Enable unit tests
• Required for updating flake8