title: tsconfig.json typeroots custom path not picked up
body: <p>I have some custom .d.ts files and I want tsc to pick up these files when compiling.  In order to get this done I modify the tsconfig.file to include the following</p>
  
  <pre><code>"typeRoots": [
        "../node_modules/@types",
        "./app/modules"
      ]
  </code></pre>
  
  <p>./app/modules is where my custom .d.ts file resides.  Inside the ./app/modules folder I have the following file myModule.d.ts</p>
  
  <pre><code>export declare module myModule {
    function Login();
    function Logout();
  }
  </code></pre>
  
  <p>Now inside my other typescript file I have the following import </p>
  
  <pre><code>import { myModule } from 'myModule';
  </code></pre>
  
  <p>Here I get the following error <strong>Cannot find module 'myModule'.</strong></p>