title: How to add angular-pdf in ionic2?
body: <p>I want to add angular-pdf to show pdf in my ionic 2, but found most setup are based on ionic 1. for example, after copying angular-pdf.js into my project, the instructions said "Include the directive as a dependency when defining the angular app":</p>
  
  <pre><code>var app = angular.module('App', ['pdf']);
  </code></pre>
  
  <p>but in ionic 2, how can I add angular-pdf as library so that I can use ng-pdf tag?</p>