Fix image tags in docker-compose

Author: vanstee

docker-compose.yml

@@ -50,7 +50,7 @@ services:
     extends:
       file: docker-compose.common.yml
       service: common
-    image: operable/cog:1.0
+    image: operable/cog:1.0-beta.2
     environment:
       - COG_MQTT_HOST=0.0.0.0
       - DATABASE_URL=ecto://cog:cog@postgres:5432/cog
@@ -66,7 +66,7 @@ services:
     extends:
       file: docker-compose.common.yml
       service: common
-    image: operable/relay:1.0
+    image: operable/relay:1.0-beta.2
     privileged: true
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock