title: How to break up command in CircleCI yml to multiple lines?
body: <p>I have a CircleCI configuration file that looks like so:</p>
  
  <pre><code># Customize test commands
  test:
    override:
      - docker run -e VAR1=$VAR! -e VAR2=$VAR2 -e $VAR3-$VAR3 --entrypoint python my_image:latest -m unittest discover -v -s test
  </code></pre>
  
  <p>How can I break up the <code>docker run</code> command into multiple lines like:</p>
  
  <pre><code>docker run \
  -e VAR1=$VAR! \
  -e VAR2=$VAR2 \
  -e $VAR3-$VAR3 \
  --entrypoint python my_image:latest \
  -m unittest discover -v -s test
  </code></pre>
  
  <p>I've tried using the <code>|</code> operator for yaml, but CircleCI was unable to parse because it expects <code>override</code> to be a list.</p>
  
  <pre><code># Customize test commands
  test:
    override: |
      docker run \
        -e VAR1=$VAR! \
        -e VAR2=$VAR2 \
        -e $VAR3-$VAR3 \
        --entrypoint python my_image:latest \
        -m unittest discover -v -s test
  </code></pre>