Feature request - async Redis client

[zoltan-fedor]

Hi,
Thanks for the great library.

I was looking at the code and I saw that it supports caching async endpoints, but not yet support the use of a Redis async client.

redis-py (https://github.com/redis/redis-py/) now since v4.2.x supports async connection to Redis, so it should be possible to take advantage of that and add it as an option next to the current sync Redis client.
I believe this would be a great addition and would make this library perfect.

Ps.: If you want, I could make a PR for it once I have the time.