title: Vue not rendering new data
body: <p>I'm trying to use Vue and change a DOM, using informations that i got from a POST method.
  I have a component named treeview:</p>
  
  <pre><code>&lt;div id="treeview" class="col-sm-3" style="overflow-y: auto"&gt;
    &lt;ul&gt;
      &lt;li v-for="file in files" v-on:click="openFile(file)"&gt;
        &lt;i v-bind:class="file.filetype"&gt;&lt;/i&gt; {{file.name}}
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And two functions to fill it up:</p>
  
  <pre><code>function ReadRede(){
    $.ajax({
      type: 'POST',
      contentType: 'application/json',
      url: "/ReadRede",
      success: function(datarec) {
        console.log(datarec);
        var filedropdown = new Vue({
          el: '#treeview',
          data: {
            files: JSON.parse(datarec)
          }
        })
        filedropdown.files = JSON.parse(datarec);
      }
    });
  }
  
  function ReadLocal(){
    var pathAtt = {
      path: localStorage.local
    }
    $.ajax({
      type: 'POST',
      contentType: 'application/json',
      url: "/ReadLocal",
      data: JSON.stringify(pathAtt),
      success: function(datarec) {
        console.log(datarec);
        var filedropdown = new Vue({
          el: '#treeview',
          data: {
            files: JSON.parse(datarec)
          }
        })
        filedropdown.files = JSON.parse(datarec);
      }
    });
  }
  </code></pre>
  
  <p>What is the correct way to make it change the DOM?</p>