title: Vuejs slice function not reactive
body: <p>I'm using 
  - laravel
  - blade
  -vuejs</p>
  
  <p>For one case i have splice not reactive on array. 
  So i have an ul/li (  i have remove css and other stuff )</p>
  
  <pre><code>&lt;ul&gt;
          &lt;template v-for="(user, index) in availableUsers"  &gt;
          &lt;li v-bind:data-user="user.id" v-bind:data-index="index" &gt;
              @{{user.fullName}}
              &lt;button id=btnRemove&gt;                            
          &lt;/li&gt;
     &lt;/template&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>in my vue instance code i have a function removeFromAvailable. 
   i do a call to myvue.availableUsers.slice(index, 1).
  the method receive the good index. </p>
  
  <pre><code>removeFromAvailable : function(index) {
          console.log(index);
          myVue.availableUsers.slice(index, 1);
  }
  </code></pre>
  
  <p>It's still in the list. I'm confused because it's first time it's not working. </p>
  
  <p>Any idea why it's not reactive?</p>