Add setup.py for releasing package to expose common utilities in PythonRobotics.

I think the utilities in this package are helpful, this should be used as a package and should be installed via pip.
https://github.com/AtsushiSakai/PythonRobotics/tree/master/utils

This is the time to release as an official PyPI package. And when this package is mature, we can start to add each algorithm to the package step by step.