title: Ionic 2 Alert Component property create does not exist on type Alert
body: <p>I've import <code>Alert Component</code> in my <code>ionic 2</code> project like this :</p>
  
  <pre><code>import {Alert } from 'ionic-angular';
  </code></pre>
  
  <p><strong>Usage:</strong></p>
  
  <pre><code>let alert = this.alert.create({
      title: 'New Friend!',
      subTitle: 'Your friend, Obi wan Kenobi, just accepted your friend request!',
        buttons: ['OK']
      });
  alert.present();
  </code></pre>
  
  <p><strong>But my error is :</strong> <code>Property create does not exist on type Alert.</code></p>
  
  <p><strong>Ionic Info :</strong></p>
  
  <pre><code>Cordova CLI: 6.3.0
  Gulp version:  CLI version 1.2.1
  Gulp local:   Local version 3.9.1
  Ionic Framework Version: 2.0.0-beta.10
  Ionic CLI Version: 2.0.0-beta.37
  Ionic App Lib Version: 2.0.0-beta.20
  ios-deploy version: 1.8.6 
  ios-sim version: 5.0.8 
  OS: Mac OS X El Capitan
  Node Version: v5.12.0
  Xcode version: Xcode 7.3 Build version 7D175 
  </code></pre>
  
  <p><strong>how can i solve it ?</strong></p>