title: ngbPopover not showing up
body: <p>I'm trying to use the popover from ng-bootstrap (<a href="https://ng-bootstrap.github.io/#/components/popover" rel="nofollow">https://ng-bootstrap.github.io/#/components/popover</a>) in my Angular2/Typescript app.</p>
  
  <p>I don't even know how to state the question as there are no errors and yet, the popover is not showing.</p>
  
  <p>this is the code that I have:</p>
  
  <pre><code> &lt;div ngbPopover="You see, I show up on hover!" 
        placement="top" triggers="mouseenter:mouseleave" title="Pop title"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>And this is my app config:</p>
  
  <pre><code>import {NgbModule} from '@ng-bootstrap/ng-bootstrap';
  
  @NgModule({
      declarations: [
          AppComponent,
          HomeComponent,
          DependenciesComponent,
          TraceChartComponent
      ],
      imports: [
         NgbModule, 
      ...
  </code></pre>
  
  <p>Which is pretty much taken from their example site.</p>
  
  <p>I'm fairly sure I've got all the required javascripts included as the <code>ngbTooltip</code> do work.</p>
  
  <p>Is there anything else I need to do that I am missing here?</p>