Development: start Redis with a password (#164)

* Development: start Redis with a password

* Redis: use the newest version deployed in production

Author: humitos

dockerfiles/docker-compose.yml

@@ -145,7 +145,9 @@ services:
     command: ["../../docker/build.sh"]
 
   cache:
-    image: redis:6.0.5
+    image: redis:6.2.6  # Match production version
+    command: >
+          --requirepass "redispassword"
     networks:
       readthedocs: