title: Typescript Error, Cannot find name 'gapi', transpile failed
body: <p>I trying to implement google auth in my ionic2 app. I need it works in browser. So, I installed:</p>
  
  <pre><code>npm install --save @types/gapi
  npm install --save @types/gapi.auth2
  </code></pre>
  
  <p>There is two warnings:</p>
  
  <blockquote>
    <p>npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0
    (node_modules\chokidar\node_modules\fsevents): </p>
    
    <p>npm WARN notsup
    SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for
    fsevents@1.0.15: wanted {"os":"darwin","arch":"any"} (current:
    {"os":"win32","arch":"x64"})</p>
  </blockquote>
  
  <p>In node_modules folder I have gapi and gapi.auth2 folders but I have typescript error: Cannot find name 'gapi', transpile failed.</p>
  
  <p>I installed</p>
  
  <pre><code>npm install typings -g
  typings install dt~gapi --global --save
  typings install dt~gapi.auth2 --global --save
  </code></pre>
  
  <p>Still have the same error: Cannot find name 'gapi', transpile failed</p>
  
  <p>my code:</p>
  
  <pre><code>auth2: any;
  
  login() {
        gapi.load('auth2', () =&gt; {
            this.auth2 = gapi.auth2.init({
               client_id: 'xxxxxxxxx.apps.googleusercontent.com',
               scope: 'https://www.googleapis.com/auth/userinfo.email'
            });
          });
        };
  </code></pre>
  
  <p>my package.json:</p>
  
  <pre><code>"@angular/core": "2.2.1",
  "ionic-angular": "2.0.0-rc.4",
  "ionic-native": "2.2.11",
  "rxjs": "5.0.0-beta.12",
  "typescript": "2.0.9"
  </code></pre>