title: bootstrap 4 animate column width change
body: <p>I have two columns like this:</p>
  
  <pre><code>&lt;div class="container"&gt;
      &lt;div class="row"&gt;
          &lt;div class="col-9"&gt;&lt;/div&gt;
          &lt;div class="col-3"&gt;&lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I am switching the classnames via angular to be  <code>col-8 offset-2</code> and <code>col-0</code> . <code>col-0</code> is <code>width:0;margin:0;padding:0</code>.</p>
  
  <p>I am wondering how to animate both the width, and the positions of columns.</p>