* Remove remove_route, deprecated in 19.6.
* No need for py35 compat anymore.
* Rewrite asyncio.coroutines with async/await.
* Remove deprecated request.raw_args.
* response.text() takes str only: avoid deprecation warning in all but one test.
* Remove unused import.
* Revert unnecessary deprecation warning.
* Remove apparently unnecessary py38 compat.
* Avoid asyncio.Task.all_tasks deprecation warning.
* Avoid warning on a test that tests deprecated response.text(int).
* Add pytest-asyncio to tox deps.
* Run the coroutine returned by AsyncioServer.close.
Co-authored-by: L. Kärkkäinen <tronic@users.noreply.github.com>