Bump redis from 3.2.1 to 4.5.3

Bumps [redis](https://github.com/redis/redis-py) from 3.2.1 to 4.5.3.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@3.2.1...v4.5.3)

---
updated-dependencies:
- dependency-name: redis
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
-redis==3.2.1
+redis==4.5.3
 requests==2.22.0
 slackclient==2.8.0
 zulip==0.8.1