title: Transition-group not working
body: <p><a href="https://codepen.io/joshuajazleung/pen/BJgXYp" rel="nofollow noreferrer">https://codepen.io/joshuajazleung/pen/BJgXYp</a></p>
  
  <p>I have this transition-group which I expect to have fade effect when I click the 'CONSTRUCTION PROGRESS' tab, but no transition is seen. </p>
  
  <pre><code>&lt;transition-group name="fade" class="row no-gutters" v-show="currentTab !== 'living'"&gt;
    &lt;div class="col-6 pr-3 pb-3" v-for="(item, index) in constructionGallery" :key="'construction' + item"&gt;
      &lt;img :src="item.photoThumbSmall" alt="Gallery Photo index" class="img-fluid"&gt;
      &lt;p&gt;fserf&lt;/p&gt;
    &lt;/div&gt;
  &lt;/transition-group&gt;
  </code></pre>
  
  <p>From what I see from the Chrome Inspector, no classes are added to the transitioned elements.</p>
  
  <p>What did I do wrong?</p>