* Problem: Source files contain no license info
Solution: Add comments with SPDX license info to source files
* Python 3 files don't need # -*- coding: utf-8 -*-
Solution: Random failure of test
`tests/test_events.py::test_event_handler_raises_when_called_after_start` seem
to be because of `get_nowait` which returns way to quickly even when the queue
has data. Increasing timeout seems to fix the issue.