title: Setting unknown property: dektrium\user\models\User::confirmed_at
body: <p>I have problem with dektrium\yii2-user when sign up form submitted going to error <strong>Setting unknown property: dektrium\user\models\User::confirmed_at</strong> </p>
  
  <p>i just setup config </p>
  
  <pre><code>'modules' =&gt; [
          'user' =&gt; [
              'class' =&gt; 'dektrium\user\Module',
          ],
  </code></pre>
  
  <p>help me out this error</p>