title: Custom component in ionic v3
body: <p>I wanted to create a simple component and include it on a page. I created it with <code>ionic g component my-header</code> (ionic-cli v3 beta), fixed the IonicPageModule bug and then added  to another page. I then get this error:</p>
  
  <pre><code>Error: Uncaught (in promise): Error: Template parse errors:
  'my-header' is not a known element:
  1. If 'my-header' is an Angular component, then verify that it is part of this module.
  2. If 'my-header' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.
  </code></pre>
  
  <p>The "MyHeaderComponent" was added to the @NgModule declarations automatically.</p>
  
  <p>Thanks for your help.</p>
  
  <p>EDIT:</p>
  
  <p>The component is located inside my <code>components</code> folder:</p>
  
  <p>components/my-header/my-header.html</p>
  
  <pre><code>&lt;div&gt;
    {{text}}
  &lt;/div&gt;
  </code></pre>
  
  <p>components/my-header/my-header.module.ts</p>
  
  <pre><code>import { NgModule } from '@angular/core';
  import { IonicModule } from 'ionic-angular';
  import { MyHeaderComponent } from './my-header';
  
  @NgModule({
    declarations: [
      MyHeaderComponent,
     ],
    imports: [
      IonicModule,
    ],
    exports: [
      MyHeaderComponent
    ],
    entryComponents:[
      MyHeaderComponent
    ]
  })
  export class MyHeaderComponentModule {}
  </code></pre>
  
  <p>components/my-header/my-header.scss</p>
  
  <pre><code>my-header {}
  </code></pre>
  
  <p>components/my-header/my-header.ts</p>
  
  <pre><code>import { Component } from '@angular/core';
  
  @Component({
    selector: 'my-header',
    templateUrl: 'my-header.html'
  })
  export class MyHeaderComponent {
  
    text: string;
  
    constructor() {
      console.log('Hello MyHeaderComponent Component');
       this.text = 'Hello World';
    }
  
  }
  </code></pre>
  
  <p>app/app.module.ts</p>
  
  <pre><code>/* imports */
  import { MyHeaderComponent } from '../components/my-header/my-header';
  
  @NgModule({
    declarations: [
      MyApp,
      MyHeaderComponent
    ],
  ...
  </code></pre>
  
  <p>pages/home/home.html</p>
  
  <p></p>