Add `asyncmy` support
Added initial support for the ``asyncmy`` asyncio database driver for MySQL
and MariaDB. This driver is very new, however appears to be the only
current alternative to the ``aiomysql`` driver which currently appears to
be unmaintained and is not working with current Python versions. Much
thanks to long2ice for the pull request for this dialect.
Fixes: #6993
Closes: #7000
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7000
Pull-request-sha:
f7d6c811fc72324a83c8af635bbca8b268b0098e
Change-Id: I4ef54b43334feff7e3a710fc4de6821437f3bb68