message: Update Angular 2+ example to include environment config and test command
diff: @@ -15,7 +15,8 @@ export class AirbrakeErrorHandler implements ErrorHandler {
  constructor() {
  this.airbrake = new Notifier({
  projectId: 1,
  - projectKey: 'FIXME'
  + projectKey: 'FIXME',
  + environment: 'production'
  });
  }
  @@ -49,3 +50,10 @@ import { AirbrakeErrorHandler } from './error_handler';
  })
  export class AppModule { }
  ```
  +
  +To test that Airbrake has been installed correctly in your Angular project,
  +just open up the JavaScript console in your internet browser and paste in:
  +
  +```js
  +window.onerror("TestError: This is a test", "path/to/file.js", 123);
  +```
  