* MQTT Cover - Add availability_topic for online/offline status
Added topic, configurable payloads, and tests.
* Merge branch 'dev' into mqtt-cover-availability
* Revert "Merge branch 'dev' into mqtt-cover-availability"
This reverts commit 46d29794ba.
* Added newline at end of test_mqtt.py
* Fixed lint issue (newline at EOF)
* Fixed lint issue (newline at EOF)
* Updated call signature for other tests
* Fixed availability message callback