* Use DataUpdateCoordinator for wemo
* Rename DeviceWrapper->DeviceCoordinator and make it a subclass of DataUpdateCoordinator
* Rename async_update_data->_async_update_data to override base class
* Rename: device -> coordinator
* Periodically attempt to discover new wemo devices
* Set self._stop=None after stopping the periodic discovery task
* Use the async_fire_time_changed test helper to simplify test_discovery
* Stop the pywemo registry outside of the async loop
* Add a comment describing why async_fire_time_changed is used
* Add tests for the wemo component.
* Prefer mock tools from tests.async_mock over importing asynctest directly
* Avoid using `entity/entities` except when referring to an `Entity` instance in wemo tests
* Remove the overridden event_loop fixture from the wemo tests
* Patch the library code, not the integration code, in the wemo tests
Eric Severance
Erik Montnemery
Franck Nijhof