title: NgbModule ng-bootstrap for angular2 is not working
body: <p>Imported it in app.module.ts like,</p>
  
  <pre><code>import {NgbModule} from '@ng-bootstrap/ng-bootstrap';
  </code></pre>
  
  <p>added it in </p>
  
  <pre><code>imports:[NgbModule.forRoot()]
  </code></pre>
  
  <p>while compiling it is giving </p>
  
  <pre><code>WARNING in ./~/@ng-bootstrap/ng-bootstrap/datepicker/datepicker-input.js
  188:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/modal/modal-window.js
  61:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/popover/popover.js
  119:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/buttons/radio.js
  108:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/buttons/radio.js
  212:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/typeahead/typeahead.js
  224:12-21 "export 'Renderer2' was not found in '@angular/core'
  
  WARNING in ./~/@ng-bootstrap/ng-bootstrap/tooltip/tooltip.js
  131:12-21 "export 'Renderer2' was not found in '@angular/core'
  webpack: Compiled with warnings.
  </code></pre>
  
  <p>What could be wrong with the initialization, can anyone help?
  Thank you.</p>