v0.22.0

PyPI package: https://pypi.org/project/python-redux/0.22.0

Changes:

• test: make sure pytest exits completely after running async tests
• refactor: in _wait_for_store_to_finish, instead of waiting with asyncio.sleep, run the store event loop when conditions are not satisfied
• refactor: directly run _handle_finish_event in the store event loop when FinishEvent is dispatched, previously it used to be a normal subscribe_event, events registered in subscribe_event run in SideEffectRunnerThread and it runs them with the task_runner, and there is no guarantee task_runner runs tasks after FinishEvent is dispatched