Add redis to docker-compose.yml (#112)

Celery is using it as the results backend

Author: javihernandez

docker-compose.yml

@@ -33,6 +33,7 @@ services:
       - ".:/code"
     depends_on:
       - rabbitmq
+      - redis
 
   scheduler:
     image: alts-scheduler:latest
@@ -52,6 +53,9 @@ services:
     depends_on:
       - rabbitmq
 
+  redis:
+    image: redis
+
   alts_tests:
     image: alts-tests:latest
     build: