title: How to add custom class to ng-bootstrap tooltip
body: <p>I'm trying to add a custom class to an ng-bootstrap tooltip but it won't apply it.</p>
  
  <p>HTML</p>
  
  <pre><code>&lt;i class="fa fa-info-circle" aria-hidden="true" [ngbTooltip]="infoTooltipTemplate" [tooltipClass]="info-tooltip" placement="top"&gt;&lt;/i&gt;
  </code></pre>
  
  <p>CSS</p>
  
  <pre><code>.info-tooltip .tooltip-inner {
    max-width: 340px;
    text-align: left;
    background-color: #fff;
    color: #000;
    border-radius: 30px;
    box-shadow: 0 0 3px #00000040;
  }
  </code></pre>
  
  <p>The styling for the tooltip still remains the same as the default styling. I'm working on Angular 7 with @ng-bootstrap version 4.2.2</p>