title: No Provider for AuthHttp! Angular2-Jwt provider issue
body: <p>At least I thought I was providing correctly. Below are the relevant snippets of my app.module file and the service in which I use AuthHttp. I followed the configuration in the ReadMe for creating the factory method to provide for AuthHttp, but there is a persisting issue with it not being recognized in my service. I've read the literature on nested dependency injections, and I feel as though I'm doing things correctly.</p>
  
  <p>app.module.ts</p>
  
  <pre><code>import { Http, RequestOptions } from '@angular/http';
  import { provideAuth, AuthHttp, AuthConfig } from 'angular2-jwt/angular2-jwt';
  
  export function authHttpServiceFactory(http: Http, options: RequestOptions) {
    return new AuthHttp(new AuthConfig(), http, options);
  }
  
  @NgModule({
      declarations: [
          AppComponent,
          ButtonFormComponent,
  ...
  imports: [
          BrowserModule,
          FormsModule,
          HttpModule,
          RouterModule,
          AppRoutingModule
      ],
      providers: [
          {
              provide: LocationStrategy,
              useClass: HashLocationStrategy
          },
          {
              provide: AuthHttp,
              useFactory: authHttpServiceFactory,
              deps: [Http, RequestOptions]
          },
  </code></pre>
  
  <p>employee.service.ts</p>
  
  <pre><code>import { AuthHttp } from 'angular2-jwt/angular2-jwt';
  import { Observable } from 'rxjs/Observable';
  import 'rxjs/add/operator/catch';
  import 'rxjs/add/operator/map';
  import 'rxjs/add/observable/throw';
  
  import { ApiSettings } from './api-settings';
  
  
  @Injectable()
  export class EmployeeService {
      api: String;
      auth: String;
      constructor(private http: Http, private authHttp: AuthHttp) {
          this.api = ApiSettings.API;
          this.auth = ApiSettings.Auth;
      }
  </code></pre>