title: Unable to run images created by docker compose independently
body: <p>I have following docker compose file. Which creates two images api and scheduler. api exposes end point and scheduler runs at a particular time.  Both images run fine when I use <code>docker-compose up</code> but 
  when I try to run images independently by <code>docker run -itd --name api   api:latest</code> and 
  <code>docker run  -itd --name schedule scheduler:latest</code> it does not run ok. In both cases it shows CMD as python3 in container. I am expecting it to run <code>CMD  ["gunicorn",  "--bind", "0.0.0.0:5000",  "run_api:application", "&amp;"]</code> for api container.</p>
  
  <pre><code>``
  version: '3'
  services:
    api:
      container_name: api
      build:
        context: .
        dockerfile: Dockerfile
      command: ["gunicorn",  "--bind", "0.0.0.0:5000",  "run_api:application", "&amp;"]
      ports:
        - "5000:5000"
      restart: always
      environment:
        - config=${config}
    scheduler:
      container_name: scheduler
      build:
        context: .
        dockerfile: Dockerfile
      command: ["sh", "-c", "python3 run_scheduler.py"]
      ports:
          - "80:80"
      restart: always
      environment:
        - config=${config}
  ``
  </code></pre>