title: ngbAccordion class not defined with ng2-bootstrap
body: <p>I am trying to implement a simple accordion style using Angular 2 and ng2-bootstrap. I'm using the Angular2 Quickstart files as the starting point and modified the files to add ng2-bootstrap, bootstrap.css. The index.html, app.module.ts, app.component.ts, and app.component.html files are listed below. The ng2-bootstrap 'Alert' functions correctly, but I receive the following error for the 'Accordion' element:</p>
  
  <pre><code>zone.js:420 Unhandled Promise rejection: Template parse errors:
  There is no directive with "exportAs" set to "ngbAccordion" ("
  &lt;br&gt; ......
  </code></pre>
  
  <p>Any ideas on the cause of the error and potential fixes?</p>
  
  <p>index.html</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;title&gt;Angular QuickStart&lt;/title&gt;
      &lt;meta charset="UTF-8"&gt;
      &lt;meta name="viewport" content="width=device-width, initial-scale=1"&gt;
      &lt;base href="/"&gt;
      &lt;link rel="stylesheet" href="styles.css"&gt;
  
      &lt;!-- Import bootstrap here --&gt;
      &lt;link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"&gt;
  
      &lt;!-- Polyfill(s) for older browsers --&gt;
      &lt;script src="node_modules/core-js/client/shim.min.js"&gt;&lt;/script&gt;
      &lt;script src="node_modules/zone.js/dist/zone.js"&gt;&lt;/script&gt;
      &lt;script src="node_modules/systemjs/dist/system.src.js"&gt;&lt;/script&gt;
  
      &lt;script src="systemjs.config.js"&gt;&lt;/script&gt;
      &lt;script&gt;
        System.import('main.js').catch(function(err){ console.error(err); });
      &lt;/script&gt;
    &lt;/head&gt;
  
    &lt;body&gt;
      &lt;my-app&gt;Loading AppComponent content here ...&lt;/my-app&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>app.module.ts</p>
  
  <pre><code>import { NgModule }      from '@angular/core';
  import { BrowserModule } from '@angular/platform-browser';
  
  import { AlertModule } from 'ng2-bootstrap';
  import { AccordionModule } from 'ng2-bootstrap';
  
  import { AppComponent }  from './app.component';
  
  @NgModule({
  
    imports:      [ 
      BrowserModule,
      AlertModule.forRoot(),
      AccordionModule.forRoot()
       ],
    declarations: [ AppComponent ],
    bootstrap:    [ AppComponent ]
  })
  export class AppModule { }
  </code></pre>
  
  <p>app.component.ts</p>
  
  <pre><code>import { Component } from '@angular/core';
  
  @Component({
    selector: 'my-app',
    templateUrl: './app/app.component.html'
  })
  export class AppComponent  { name = 'Angular'; }
  </code></pre>
  
  <p>app.component.html</p>
  
  <pre><code>&lt;h1&gt;Hello {{name}}&lt;/h1&gt;
  &lt;alert type="success" dismissible="true"&gt;
      Well Done!
  &lt;/alert&gt;
  &lt;br&gt;
  
  &lt;ngb-accordion #acc="ngbAccordion" activeIds="ngb-panel-0"&gt;
    &lt;ngb-panel title="Simple"&gt;
      &lt;template ngbPanelContent&gt;
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia
        aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor,
        sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica,
        craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings
        occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus
        labore sustainable VHS.
      &lt;/template&gt;
    &lt;/ngb-panel&gt;
    &lt;ngb-panel&gt;
      &lt;template ngbPanelTitle&gt;
        &lt;span&gt;&amp;#9733; &lt;b&gt;Fancy&lt;/b&gt; title &amp;#9733;&lt;/span&gt;
      &lt;/template&gt;
      &lt;template ngbPanelContent&gt;
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia
        aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor,
        sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica,
        craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings
        occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus
        labore sustainable VHS.
      &lt;/template&gt;
    &lt;/ngb-panel&gt;
    &lt;ngb-panel title="Disabled" [disabled]="true"&gt;
      &lt;template ngbPanelContent&gt;
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia
        aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor,
        sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica,
        craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings
        occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus
        labore sustainable VHS.
      &lt;/template&gt;
    &lt;/ngb-panel&gt;
  &lt;/ngb-accordion&gt;
  </code></pre>