title: Tabs Not Showing in Ionic 2
body: <p>I have a tab inside a modal. I need to show the 3 tabs inside the modal. However, it doesn't show up. It just appear a blank. </p>
  
  <pre><code>&lt;ion-header&gt;
      &lt;ion-navbar&gt;
      &lt;ion-buttons left&gt;
        &lt;button ion-button icon-only (click)="closeModal()"&gt;
          &lt;ion-icon name="arrow-back"&gt;&lt;/ion-icon&gt;
        &lt;/button&gt;
      &lt;/ion-buttons&gt;
      &lt;ion-title class="filter"&gt;Filter&lt;/ion-title&gt;
      &lt;/ion-navbar&gt;
  &lt;/ion-header&gt;
  
  &lt;ion-content padding&gt;
    &lt;ion-tabs&gt;
    &lt;ion-tab&gt;Hello&lt;/ion-tab&gt;
    &lt;ion-tab&gt;Hello&lt;/ion-tab&gt;
    &lt;ion-tab&gt;Hello&lt;/ion-tab&gt;
  &lt;/ion-tabs&gt;
  &lt;/ion-content&gt;
  </code></pre>