title: Django assert that response contains one of a list of possible strings
body: <p>I'm writing tests for my Django app using the built-in testing tools. Right now I'm trying to write a test for a page that displays a list of a user's followers. When a user has no followers the page displays a message randomly picked from a list of strings. As an example:</p>
  
  <pre><code>NO_FOLLOWERS_MESSAGES = [
      "You don't have any followers.", 
      "Sargent Dan, you ain't got no followers!"
  ]
  </code></pre>
  
  <p>So now I want to write a test that asserts that the response contains one of those strings. If I was only using one string, I could just use <code>self.assertContains(request, "You don't have any followers.")</code> but I'm stuck on how to write the test with multiple possible outcomes. Any help would be appreciated.</p>