title: getting route name not the route path in twig symfony
body: <p>i'm developing an application with symfony3.<br>
  I want to get route name in twig. i did this :
  <br></p>
  <pre><code> {% set current_path = path(app.request.get('_route')) %}
   {{ current_path }}
  </code></pre>
  <p>it displays the url of the current page. But i want to get route name not the path.
  example :</p>
  <pre><code>personnel_index:
      path:     /liste
      defaults: { _controller: &quot;PersonnelBundle:Personnel:index&quot; }
      methods:  GET
  </code></pre>
  <p>must return : personnel_index</p>
  <blockquote>
  <p>so how can i get the route name</p>
  </blockquote>