Unsupported config option for services service: 'httpd'
<p>I am getting this on Ubuntu with a fresh install of Docker 1.12.0</p>

<p>It works on all other colleagues installations with the same version of Docker.</p>

<p>This is the docker-compose.yml</p>

<pre><code>version: '2'

networks:
  backend:

services:
  httpd:
    image: httpd:2.4
    depends_on:
      - tomcat
    networks:
      - backend
    ports:
      - "80:80"
    volumes:
      - ./httpd/httpd.conf:/usr/local/apache2/conf/httpd.conf

  tomcat:
    image: tomcat:8.0-jre8-alpine
    depends_on:
      - mongodb
    networks:
      - backend
    ports:
      - "8080:8080"
    volumes:
      - ./tomcat/webapps:/usr/local/tomcat/webapps/
    environment:
      - ITONICS_CONFIG=docker
      - CATALINA_OPTS=-Xms512M -Xmx2048M

  mongodb:
    image: mongo:3.2
    volumes:
      - ./mongo/db:/data/db
    networks:
      - backend
    ports:
      - "27017:27017"
</code></pre>