Log Message:
Version 2.0.3:
* Add ``python_requires`` in ``setup.py``

Version 2.0.2:
* Handle ``text-align`` in textPath tags
* Test with Python 3.6

Version 2.0.1:
* Don't crash on relative refs with no input URL

Version 2.0.0:
* Drop Python 2 support
* Drop pycairo support
* Rely on cairocffi, lxml, cssselect, pillow and tinycss
* Fix markers
* Fix URL/id handling
* Use bounding boxes for gradients
* Split deployment and development tests
* Add a scale option
* Add a parent size option
* Test with Travis