* Do not use pychromecast.Chromecast for Cast Groups
pychromecast.Chromecast creates Chromecast instance with friendly_name and cast_type of the device and not of a group.
Which leads to collisions
* Update cast.py
* using hass.data
* Fixed and extended tests
* Line length in tests
* Lint in tests
* No longer require pyunify during tests
* No longer require cast during tests
* No longer required dependency for tests
* No longer require pymochad for tests
* Astral is a core dependency
* Avoid having to install datadog dependency during tests
* CMUS test doesn't test anything
* Frontier Silicon doesn't test anything
* No longer require mutagen
* Update requirements_test_all.txt
* Remove stale comment
* Fixes an issue where Chromecast audio groups were not properly discovered
* Forgot to commit the main fix
* Removes unused variable
* Doesn't use a protected API anymore
* PR remarks
* Fixes tests, adds comment
* Restores line as it was in the original commit, rephrases comment
* Should fix lint issues
* Trailing whitespace
* Some more lint
