title: Typescript 2 definitions for mocha, jasmine cause duplicate identifiers
body: <p>Steps to reproduce:<br>
  1) <code>npm install @types/mocha @types/jasmine</code><br>
  2) <code>tsc</code></p>
  
  <pre><code>node_modules/@types/jasmine/index.d.ts(9,18): error TS2300: Duplicate identifier 'describe'.
  node_modules/@types/jasmine/index.d.ts(11,18): error TS2300: Duplicate identifier 'xdescribe'.
  ...
  node_modules/@types/mocha/index.d.ts(33,13): error TS2300: Duplicate identifier 'describe'.
  node_modules/@types/mocha/index.d.ts(34,13): error TS2300: Duplicate identifier 'xdescribe'.
  ...
  </code></pre>
  
  <p>My project structure:</p>
  
  <pre><code>node_modules
  test.ts
  tsconfig.json
  </code></pre>
  
  <p>My code:</p>
  
  <pre><code>const a: number = 9;
  </code></pre>
  
  <p>My tsconfig.json:</p>
  
  <pre><code>{
    "compilerOptions": {
      "target": "es5",
      "module": "commonjs",
      "moduleResolution": "node"
    }
  }
  </code></pre>