Bump redis from 4.4.0 to 4.5.1

Bumps [redis](https://github.com/redis/redis-rb) from 4.4.0 to 4.5.1.
- [Release notes](https://github.com/redis/redis-rb/releases)
- [Changelog](https://github.com/redis/redis-rb/blob/master/CHANGELOG.md)
- [Commits](redis/redis-rb@v4.4.0...v4.5.1)

---
updated-dependencies:
- dependency-name: redis
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -1526,7 +1526,7 @@ GEM
       railties (>= 3.2)
       tilt
     redcarpet (3.5.1)
-    redis (4.4.0)
+    redis (4.5.1)
     remotipart (1.4.4)
     responders (3.0.1)
       actionpack (>= 5.0)