Remove Python file docstrings

Previously, whenever you used this on a robot file, it would keep in unnecessary comments that add extra characters to the end file. By adding docstrings=True, minipy will filter out those comments and other docstrings.

For example, using the previous version on my current Curtis (with comments left in) produces a file with ~1250 characters. Using this version on Curtis produces an net result of 1213 characters, significiantly better.