Bump redis from 4.1.3 to 4.1.4 (#968)

Bumps [redis](https://github.com/redis/redis-py) from 4.1.3 to 4.1.4.
- [Release notes](https://github.com/redis/redis-py/releases)
- [Changelog](https://github.com/redis/redis-py/blob/master/CHANGES)
- [Commits](redis/redis-py@v4.1.3...v4.1.4)

---
updated-dependencies:
- dependency-name: redis
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements_dev_optional.txt

@@ -7,7 +7,7 @@ ipytree==0.2.1
 # don't let pyup change pinning for azure-storage-blob, need to pin to older
 # version to get compatibility with azure storage emulator on appveyor (FIXME)
 azure-storage-blob==12.8.1 # pyup: ignore
-redis==4.1.3
+redis==4.1.4
 types-redis
 types-setuptools
 pymongo==4.0.1