title: Skip steps on a django FormWizard
body: <p>I have an application where there is a FormWizard with 5 steps, one of them should only appear when some conditions are satisfied.</p>
  
  <p>The form is for a payment wizard on a on-line cart, one of the steps should only show when there are promotions available for piking one, but when there are no promotions i want to skip that step instead of showing an empty list of promotions.</p>
  
  <p>So I want to have 2 possible flows:</p>
  
  <pre><code>step1 - step2 - step3
  
  step1 - step3
  </code></pre>