title: 'drive' does not exist on type 'typeof client'
body: <p>Angular 5 cannot find <code>drive</code> from <code>gapi.client</code>. What I have done is:</p>
  
  <p><code>package.json</code>:</p>
  
  <pre><code>"@types/gapi.client.drive": "^3.0.0",
  </code></pre>
  
  <p><code>tsconfig.app.json</code>:</p>
  
  <pre><code>"types": ["gapi.auth2", "gapi.client", "gapi.client.drive"]
  </code></pre>
  
  <p><code>index.html</code>:</p>
  
  <pre><code>&lt;script src="https://apis.google.com/js/platform.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>Both my editor(VS Code) and Angular report an error like below:</p>
  
  <p><code>Property 'drive' does not exist on type 'typeof client'</code></p>
  
  <p>, but <code>console.log(gapi.client.drive.files);</code> can get everything I need.</p>
  
  <p>Am I missing any library here?</p>