title: highchart export button not show
body: <p>I´m prooving highcharts with a simple graph in angular . But export button not show . I add the script in html page :</p>
  
  <pre><code>&lt;script src="https://code.highcharts.com/highcharts.js"&gt;&lt;/script&gt;
  &lt;script src="https://code.highcharts.com/modules/data.js"&gt;&lt;/script&gt;
  &lt;script src="https://code.highcharts.com/modules/exporting.js"&gt;&lt;/script&gt;  
  &lt;script src="https://code.highcharts.com/modules/offline-exporting.js"&gt;&lt;/script&gt;  
  &lt;script src="https://code.highcharts.com/modules/export-data.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>and add the properties in chart :</p>
  
  <pre><code>export :true,
  navigation: {
    buttonOptions: {
      align: 'right',
      verticalAlign: 'top',
      y: 0
    }
  },
  </code></pre>
  
  <p>but nothing.</p>
  
  <p>this is te app url :</p>
  
  <p><a href="https://stackblitz.com/edit/angular-hkncp8" rel="nofollow noreferrer">https://stackblitz.com/edit/angular-hkncp8</a></p>