title: Django messaging framework - how to only display success messages
body: <p>I'm using the Django messaging framework to display feedback messages. I can't display one the success messages.</p>
  
  <p>Here's adapted code from the solution <a href="https://stackoverflow.com/questions/2697533/displaying-django-messages-framework-messages">suggested here</a> and the docs:</p>
  
  <pre><code>{% for message in messages.success %}
      {% if 'success' in message.tags %}
      &lt;div class="success-message"&gt;{{ message }}&lt;/div&gt;
      {% endif %}
  {% endfor %}
  </code></pre>
  
  <p>This yields nothing. If I use something less discriminate, it renders my messages perfectly fine:</p>
  
  <pre><code>{% for message in messages %}
      &lt;p&gt;{{ message }}&lt;/p&gt;
  {% endfor %}
  </code></pre>
  
  <p>The view creates the messages like this:</p>
  
  <pre><code>messages.success(request, "here's a sample success message") 
  </code></pre>
  
  <p>What am I doing wrong? I'm using django 1.9.2</p>