title: <b-modal> is showing as text when using bootstrap-vue
body: <p>I'm building a modal, to edit an object from a table, but when calling a example modal, it's showing as a text. As in this image bellow: </p>
  
  <p><a href="https://i.stack.imgur.com/Zp5zL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Zp5zL.png" alt="enter image description here"></a></p>
  
  <p>Here is the code example: </p>
  
  <pre><code>    &lt;!-- Using value --&gt;
      &lt;b-button v-b-modal="'my-modal'"&gt;Show Modal&lt;/b-button&gt;
  
      &lt;!-- The modal --&gt;
      &lt;b-modal id="my-modal"&gt;Hello From My Modal!&lt;/b-modal&gt;
  </code></pre>
  
  <p>This is strange, because v-for and v-model are working normaly, but <code>&lt;b-alert&gt;</code> and <code>&lt;b-modal&gt;</code> aren't.</p>