title: Can not find module 'xlsx' in angular
body: <p>I want to import <code>xlsx</code>.</p>
  
  <p>So, i install <code>xlsx</code> using <code>npm install xlsx</code>.</p>
  
  <p>And import <code>xlsx</code> module. <code>import * as XLSX from 'xlsx';</code></p>
  
  <p>(Also I try <code>import { foo, bar } from 'xlsx';</code>)</p>
  
  <p>And run this code with Angular cli. <code>ng serve</code>.</p>
  
  <p>I use it.</p>
  
  <pre><code>Angular CLI: 1.6.1
  Node: 6.11.3
  OS: win32 x64
  Angular: 2.4.10
  ... common, compiler, compiler-cli, core, forms, http
  ... platform-browser, platform-browser-dynamic
  
  @angular/cli: 1.6.1
  @angular/router: 3.4.10
  @angular/tsc-wrapped: 0.5.2
  @angular-devkit/build-optimizer: 0.0.36
  @angular-devkit/core: 0.0.22
  @angular-devkit/schematics: 0.0.34
  @ngtools/json-schema: 1.1.0
  @ngtools/webpack: 1.9.1
  @schematics/angular: 0.1.11
  @schematics/schematics: 0.0.11
  typescript: 2.0.10
  webpack: 3.10.0
  </code></pre>
  
  <p>please help. thanks.</p>