title: How to pass command line arguments to a docker image
body: <p>I run tests inside docker image and I need to pass custom arguments 
  all the time. </p>
  
  <p>When I put arguments after image name docker thinks that argument is image name.</p>
  
  <pre><code>docker run  -t -i image-name -s test.py
  docker run  -t -i image-name -- -s test.py
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>Failed no image test_arena2.py
  </code></pre>
  
  <p>Docker version 1.11.2, build b9f10c9</p>