removing detritus

docker-compose/forums/docker-compose.yml

-db:
-  container_name: db
-  image: edxops/mysql:v1
-  environment:
-    - MYSQL_ROOT_PASSWORD=''
-  hostname: db
-  ports:
-    - 3306:3306
-
 mongo:
   container_name: mongo
   image: edxops/mongo:v2
@@ -19,16 +10,15 @@ es:
   volumes:
     - ${DOCKER_DATA_ROOT}/elasticsearch/data:/es-data
 
-memcache:
-  container_name: memcache
-  image: memcached:1.4.24
-
 forums:
   container_name: forums
   image: edxops/forums:opencraft
   ports:
     - 4567:4567
 
+#
+# TODO
+#
 #nginx:
 #  build: ../build/nginx