Remove new mock usage

This change snuck into master, change it to unittest.mock as well.

Author: s-t-e-v-e-n-k

tests/test_asyncio/test_command_policies.py

@@ -1,7 +1,7 @@
 import random
+from unittest.mock import patch
 
 import pytest
-from mock import patch
 
 from redis import ResponseError
 from redis._parsers.commands import CommandPolicies, RequestPolicy, ResponsePolicy