title: dynamic change doesn't work on vuejs input
body: <p>i'm working on a vue file and have a form : </p>
  
  <pre><code>&lt;div class="input-group"&gt;
      &lt;span class="input-group-addon"&gt;Montant&lt;/span&gt;
      &lt;input type="number" class="form-control"  v-model="amount" v-bind:value="pattern['value']"]&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>my tab pattern is loaded like that : </p>
  
  <pre><code>var request = $.ajax({
  url: '{{ path ('home') }}promos/pattern/'+value,
  })
  request.success(function(data){
      if(data['pattern']==='yes'){
          this.pattern=data[0];
          alert(this.pattern['value']);
      }
  })
  </code></pre>
  
  <p>and my instance :</p>
  
  <pre><code>var instance = new Vue({
  el: "#General",
  data: {
      [...]
      pattern: []
  }
  </code></pre>
  
  <p>and the request is made evertyime i do 'action a'. I have the right alert with the value i want everytime i do 'action a' but the input stays at 0 and won't dynamically change.</p>