deleted start command to app service since it requires the db service to be up...

deleted start command to app service since it requires the db service to be up and running, which is not guaranteed only by docker

docker-compose.yml

@@ -3,7 +3,7 @@ version: '3'
 services:
   app:
     working_dir: /usr/src/app
-    command: npm start
+    # command: npm start
     build: .
     depends_on:
       - db