Adding pure python classes/functionality#

Pure python modules can be found here <https://github.com/OpenMS/OpenMS/tree/develop/src/pyOpenMS/pyopenms>. Just add a new .py file and a new submodule will appear that can be imported with import pyopenms.submodule.

Remember to add additional requirements in the setup.py but try to avoid large dependencies unless absolutely necessary.

Testing is done via pytest. Every new module, class, function, member should be documented with Sphinx reStructuredText docstrings. See the Sphinx-RTD-Tutorial <https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html> and the Python Developers Guide <https://devguide.python.org/documentation/start-documenting/index.html>.