title: div with display: flex is not centering child div
body: <p>I have a div with a <code>display: flex</code>, and I would like to display the output in a row center. For some reason it is displaying left. I want the <code>imgBoxBot</code> to be centered inside the <code>imgBot</code> <code>div</code>. But <code>text-align: center</code> is only centering the text inside the <code>imgBoxBot</code>, how do I center the actual <code>div</code>?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>#imgBot {
    position: absolute;
    height: 100px;
    width: 100%;
    bottom: 0;
    display: flex;
    flex-direction: row;
    text-align: center;
  }
  
  #imgBoxBot {
    height: 100px;
    width: 100px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="imgBot"&gt;
    &lt;div id="imgBoxBot"&gt;
      test
    &lt;/div&gt;
    &lt;div id="imgBoxBot"&gt;
      test
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>