title: Pass variable to included playbook?
body: <p>I would like to have a master playbook, which include's other playbooks.  Is it possible to pass a variable to that included playbook?</p>
  
  <p>The normal syntax which is used for passing variables to included tasks doesn't work (see below)</p>
  
  <pre><code>- include: someplaybook.yml variable=value
  </code></pre>
  
  <p>and</p>
  
  <pre><code>- include: someplaybook.yml
    vars:
      variable: value
  </code></pre>
  
  <p>I'm running v2.0.2.0.</p>