title: vue, animation on dynamic component not triggering?
body: <p>I have a page like this:</p>
  
  <pre><code>    &lt;div class="collapse navbar-collapse" id="myNavbar"&gt;
                  &lt;ul class="nav navbar-nav"&gt;
                      &lt;li&gt;
                          &lt;a href="#" @click="currentView='create'"&gt;Create&lt;/a&gt;
                      &lt;/li&gt;
                      &lt;li&gt;
                          &lt;a href="#" @click="currentView='how'"&gt;How&lt;/a&gt;
                      &lt;/li&gt;
                      &lt;li&gt;
                          &lt;a href="#" @click="currentView='about'"&gt;About&lt;/a&gt;
                      &lt;/li&gt;
                      &lt;li&gt;
                          &lt;a href="#" @click="currentView='youtube'"&gt;Videos&lt;/a&gt;
                      &lt;/li&gt;
                  &lt;/ul&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/nav&gt;
      &lt;keep-alive&gt;
          &lt;component :is="currentView" transition="fade" transition-mode="out-in"&gt;&lt;/component&gt;
      &lt;/keep-alive&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>js:</p>
  
  <pre><code>import Vue from 'vue';
  import VueRouter from 'vue-router';
  import Create from '../components/homepage/create.vue';
  import How from '../components/homepage/how.vue';
  import About from '../components/homepage/about.vue';
  import Youtube from '../components/homepage/youtube.vue';
  import Navigation from '../components/navigation.vue';
  
  Vue.component('navigation', Navigation)
  Vue.component('create', Create)
  Vue.component('how', How)
  Vue.component('about', About)
  Vue.component('youtube', Youtube)
  
  new Vue({
      el: '#app',
      data: {
          currentView: 'create'
      }
  })
  </code></pre>
  
  <p>sass:</p>
  
  <pre><code>.fade-transition {
      transition: opacity 0.2s ease;
  }
  
  .fade-enter,
  .fade-leave {
      opacity: 0;
  }
  </code></pre>
  
  <p>and that code apparently should make the components to have animations when they switch. They do switch however without the animation, why is this happening am I missing something?</p>