title: Argument of type 'IconDefinition' is not assignable to parameter of type 'IconDefinitionOrPack'
body: <p>I'm using <a href="https://github.com/gdi2290/angular-starter" rel="noreferrer">Angular 6 angular-starter</a>  and fontawesome, followed <a href="https://github.com/FortAwesome/angular-fontawesome" rel="noreferrer">here</a> on how to install fa to ng.</p>
  
  <p>In my .ts looks like this:</p>
  
  <pre><code>import { library, dom } from '@fortawesome/fontawesome-svg-core';
  import { faInstagram } from '@fortawesome/free-brands-svg-icons/faInstagram';
  import { faLink } from '@fortawesome/free-solid-svg-icons/faLink';
  
  public ngOnInit() {
      library.add(faInstagram);
      library.add(faLink);
      dom.watch();
  }
  </code></pre>
  
  <p>Then in .html:</p>
  
  <pre><code>&lt;fa-icon [icon]="['fab', 'instagram']"&gt;&lt;/fa-icon&gt;
  </code></pre>
  
  <p>It works perfectly fine except for free brands, <code>@fortawesome/free-brands-svg-icons</code>. On build (npm start) it produces error/warning <code>Argument of type 'IconDefinition' is not assignable to parameter of type 'IconDefinitionOrPack'. 'IconDefinition' is not assignable to type 'IconPack'. signature is missing in type 'IconDefinition'.</code> on the 92% build but actually the build appears to be successful and the instagram icon shows up but I'm bothered because a red line below the code appears.</p>
  
  <p>Can someone figure it out?</p>
  
  <p>My package.json</p>
  
  <pre><code>"@fortawesome/angular-fontawesome": "^0.3.0",
  "@fortawesome/fontawesome-svg-core": "^1.2.6",
  "@fortawesome/free-brands-svg-icons": "^5.4.2",
  "@fortawesome/free-solid-svg-icons": "^5.4.1",
  </code></pre>