Bump redis from 3.0.2 to 3.1.1 in /comments-service

Bumps [redis](https://github.com/NodeRedis/node-redis) from 3.0.2 to 3.1.1.
- [Release notes](https://github.com/NodeRedis/node-redis/releases)
- [Changelog](https://github.com/NodeRedis/node-redis/blob/master/CHANGELOG.md)
- [Commits](redis/node-redis@v3.0.2...v3.1.1)

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

Author: dependabot[bot]

comments-service/package-lock.json

@@ -28,7 +28,7 @@
   "dependencies": {
     "cors": "^2.8.5",
     "express": "^4.17.1",
-    "redis": "^3.0.2",
+    "redis": "^3.1.1",
     "redis-redisearch": "stockholmux/node_redis-redisearch",
     "nconf": "^0.10.0"
   }