title: How to make the Stackblitz angular 6.0.6 find "primeng" modules? (primeng 6.0.0 added as dependency)
body: <p>I added primeng (6.0.0) as dependency in Stackblitz (Angular 6.0.6) and tried to import primeng modules (e.g. TreeModule) but it doesn't find it, you may see the code in below stackblitz:</p>
  
  <p><a href="https://stackblitz.com/edit/angular-wqef8y" rel="nofollow noreferrer">https://stackblitz.com/edit/angular-wqef8y</a></p>
  
  <p>The <a href="https://stackblitz.com/edit/angular-wqef8y?file=src%2Fapp%2Fapp.module.ts" rel="nofollow noreferrer">app.module.ts</a> can't find primeng modules.</p>
  
  <p>Any idea how to fix it?</p>