title: Ionic2 Tabs swipe back not working swipeBackEnabled
body: <p>I am developing an tabbed application I have three tabs</p>
  
  <pre><code>&lt;ion-tabs #tabsPage swipeBackEnabled="true"&gt;
    &lt;ion-tab [root]="tab1Root" tabTitle="{{'tabs.tab1'|translate}}&amp;zwnj;" tabIcon="ios-home-outline"&gt;&lt;/ion-tab&gt;
    &lt;ion-tab [root]="tab2Root" [rootParams]='filter' tabTitle="{{'tabs.tab2'|translate}}&amp;zwnj;" tabIcon="ios-list-box-outline"&gt;&lt;/ion-tab&gt;
    &lt;ion-tab [root]="tab3Root" tabTitle="{{'tabs.tab3'|translate}}&amp;zwnj;" tabIcon="md-walk"&gt;&lt;/ion-tab&gt;
  &lt;/ion-tabs&gt;
  </code></pre>
  
  <p>Tab 2 is a list view on click each item will push detail page. I was not able to use swipe back in IOS.</p>
  
  <p>When I tried to debug the properties with the below snippet</p>
  
  <pre><code>alert(this.navCtrl.canGoBack());
  alert(this.navCtrl.canSwipeBack());
  alert(this.navCtrl.swipeBackEnabled);
  </code></pre>
  
  <p>I get true, undefined, true</p>
  
  <p>If I set swipeBackEnabled to false
  I get true, false, false</p>
  
  <p>Help me here I have tried all combination to enable swipeBackEnabled.</p>
  
  <p>I tried swipeBackEnabled in 
  1.module.ts
  2.app.html</p>
  
  <pre><code>&lt;ion-nav #samNav [root]="rootPage" swipeBackEnabled="true"&gt;&lt;/ion-nav&gt;
  </code></pre>
  
  <p>3.tabs.html example above</p>
  
  <p>Nothing worked.</p>