title: Ionic-3 Avatar can't center
body: <p>I am created <code>Ionic 3 Avatar</code>, and Im try to make it center but its cant center, I don't know why can't this center, please help me to fix this
  Look my attached image, 
  <a href="https://i.stack.imgur.com/wXDeR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wXDeR.png" alt="Look at this image"></a></p>
  
  <p><strong>html</strong></p>
  
  <pre><code>&lt;ion-content padding&gt;
    &lt;ion-avatar class="avatars" &gt;
      &lt;img src="assets/imgs/pro-img.png"&gt;
    &lt;/ion-avatar&gt;
  &lt;/ion-content&gt;
  </code></pre>
  
  <p><strong>css</strong></p>
  
  <pre><code>.avatars{
     margin: auto;
  }
  </code></pre>