title: Ionic 3 can't use ion-* components inside my custom components
body: <p>I have recently upgraded to Ionic 3 from Ionic 2, and I created <strong>components.module.ts</strong> file and declared and exported each custom component I have, and then imported this single file in every page module I have.</p>
  
  <p>So now the problem is that I can't use ion-* components inside my own components, because I did not imported the <code>IonicModule.forRoot(..)</code> inside my components.module.</p>
  
  <p>The error is: </p>
  
  <blockquote>
    <p>"Template parse errors: 'ion-spinner' is not a known element ..."</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>