title: ionic2 - input type vs ngModel issue
body: <p>I have an <code>input</code> field in <code>html</code>:</p>
  
  <pre><code>&lt;input type="number" [(ngModel)]="modelnumber"&gt;
  </code></pre>
  
  <p>and <code>ts</code>:</p>
  
  <pre><code>export class SomeClass {
    modelnumber: number;
    ...
  }
  </code></pre>
  
  <p>It works on browser. But when I trying to compile to <code>ios</code> or <code>android</code>, I got this error:</p>
  
  <blockquote>
    <p>[11:00:33]  Module ''*'' has no exported member
    'Wrapper_NumberValueAccessor'.   [11:00:33]  ngc failed   </p>
  </blockquote>
  
  <p>If I either take out <code>type="number"</code> or <code>[(ngModel)]="modelnumber"</code> then the issue go away. 
  I need <code>input type</code> to be number so that when <code>touch</code> it will launch a num pad keyboard and I need it to be databind.</p>
  
  <p>How can I resolve this?</p>