title: Why symfony does not recognize the route with placeholders
body: <p>I have the following route in php</p>
  
  <pre><code>$collection-&gt;add('verify', new Route('/verify/{confirmation}', array(
     '_controller' =&gt; 'AppBundle:Verify:verify',
  )));
  </code></pre>
  
  <p>And I want to generate a url with the confirmation parameter</p>
  
  <pre><code>$url = $this-&gt;generateUrl('verify', array('confirmation' =&gt; $user-&gt;   getConfirmation())); 
  </code></pre>
  
  <p>and show it on a twig template </p>
  
  <pre><code>a href="{{ url('url') }}"
  </code></pre>
  
  <p>but I'm getting this error </p>
  
  <blockquote>
    <p>An exception has been thrown during the rendering of a template ("Unable to generate a URL for the named route "url" as such route does not exist.") in Emails/registration.html.twig at line 5.
    500 Internal Server Error - Twig_Error_Runtime
    1 linked Exception: RouteNotFoundException »</p>
  </blockquote>
  
  <p>what am I doing wrong?</p>