title: Ionic input field does not move to next field automatically
body: <p>Im using ionic 3 for my mobile application, I have some issues with my input fields which do not move automatically to the next field. For example when I click the first input filed and fill the first one, the cursor does not move to the next field. How to do that correctly?</p>
  
  <pre><code> &lt;ion-grid&gt;
        &lt;ion-row&gt;
          &lt;ion-col&gt;
            &lt;ion-item &gt;
              &lt;ion-input type="tel" placeholder="*" maxlength="1" tabindex="1"   &gt;&lt;/ion-input&gt;
            &lt;/ion-item&gt;
          &lt;/ion-col&gt;
          &lt;ion-col &gt;
            &lt;ion-item&gt;
              &lt;ion-input type="tel" placeholder="*" maxlength="1"  tabindex="2"  &gt;&lt;/ion-input&gt;
            &lt;/ion-item&gt;
          &lt;/ion-col&gt;
          &lt;ion-col &gt;
            &lt;ion-item&gt;
              &lt;ion-input type="tel" placeholder="*" maxlength="1"  tabindex="3"  &gt;&lt;/ion-input&gt;
            &lt;/ion-item&gt;
          &lt;/ion-col&gt;
          &lt;ion-col &gt;
            &lt;ion-item&gt;
              &lt;ion-input type="tel" placeholder="*" maxlength="1"  tabindex="4"   &gt;&lt;/ion-input&gt;
            &lt;/ion-item&gt;
          &lt;/ion-col&gt;
        &lt;/ion-row&gt;
  
      &lt;/ion-grid&gt;
  </code></pre>