title: Docker-compose env var not working
body: <p>I am trying to set env var in my docker compose file but the var does not seems to propagate to my docker.</p>
  
  <p>my docker-compose:</p>
  
  <pre><code>test:
    build: ./
    environment:
      TESTVAR: "YOU ARE BEST"
  </code></pre>
  
  <p>my dockerfile:</p>
  
  <pre><code>FROM alpine
  
  RUN echo test variable is: $TESTVAR
  </code></pre>
  
  <p>outputs:</p>
  
  <pre><code>Step 1/2 : FROM alpine
   ---&gt; 3fd9065eaf02
  Step 2/2 : RUN echo test variable is $TESTVAR
   ---&gt; Running in d5f5505b26db
  test variable is
  Removing intermediate container d5f5505b26db
   ---&gt; a9c019ac7eff
  Successfully built a9c019ac7eff
  Successfully tagged phpfpm_test:latest
  Recreating phpfpm_test_1 ... done
  Attaching to phpfpm_test_1
  </code></pre>
  
  <p>Am I missing something?</p>