Fixing asyncio import (#2759)

* asyncio import fix

* pinning urllib3 to fix CI (#2748)

* noqa

* fixint linters

redis/__init__.py

@@ -1,5 +1,6 @@
 import sys
 
+from redis import asyncio  # noqa
 from redis.backoff import default_backoff
 from redis.client import Redis, StrictRedis
 from redis.cluster import RedisCluster