Adapt lights simultaneously instead of one by one

[th3w1zard1]

For users using high values of send_split_delay, it's very noticeable how multiple lights in a switch turn on one after another.

[th3w1zard1]

I don't know how such a simple change doesn't pass the test.

[th3w1zard1]

I've verified on multiple different stackoverflow threads that this syntax is correct... I'm very confused about how it doesn't pass the test. I even tried increasing the time in test_manual_control (correctly this time not 87ea524 where I modified the wrong value)

With this issue and the issue from 1.10.0, I believe there's an unforeseen issue with _AsyncSingleShotTimer. We still haven't completely resolved the issue from 1.10.0: it's supposed to call the reset() function when the timer finishes yet the transition timer's reset() function is never called. We merely just check timer.is_running() as a decent band-aid in 1.11.0

[th3w1zard1]

Fixed. hass.async_create_task was the solution. It now passes the pytest.

[basnijholt]

Sorry for the delay!

This is great. I just made a small change such that the errors are preserved.