title: No provider for InjectionToken FirebaseAppConfigToken! Angular 4 , AngularFire2
body: <p>I am trying to build an app using the angular 4 and angularFire 2. My anuglar 4 app configuration is.</p>
  
  <pre><code>@angular/cli: 1.1.0
  node: 6.10.3
  os: win32 x64
  @angular/animations: 4.1.2
  @angular/common: 4.1.2
  @angular/compiler: 4.1.2
  @angular/compiler-cli: 4.1.2
  @angular/core: 4.1.2
  @angular/forms: 4.1.2
  @angular/http: 4.1.2
  @angular/platform-browser: 4.1.2
  @angular/platform-browser-dynamic: 4.1.2
  @angular/platform-server: 4.1.2
  @angular/router: 4.1.2
  </code></pre>
  
  <p>Application compiles without any issues and load all other pages except the page which has AngularFireAuth reference. When click on a page which uses AngularFireAuth breaks and below error is logged in console.</p>
  
  <pre><code>node_modules/@angular/core//bundles/core.umd.js:1091 ERROR Error: Uncaught (in promise): Error: No provider for InjectionToken FirebaseAppConfigToken!
  Error: No provider for InjectionToken FirebaseAppConfigToken!
      at injectionError (node_modules/@angular/core//bundles/core.umd.js:1238)
      at noProviderError (node_modules/@angular/core//bundles/core.umd.js:1276)
      at ReflectiveInjector_._throwOrNull (node_modules/@angular/core//bundles/core.umd.js:2777)
      at ReflectiveInjector_._getByKeyDefault (node_modules/@angular/core//bundles/core.umd.js:2816)
      at ReflectiveInjector_._getByKey (node_modules/@angular/core//bundles/core.umd.js:2748)
      at ReflectiveInjector_.get (node_modules/@angular/core//bundles/core.umd.js:2617)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:164)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:174)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:219)
      at AppModuleInjector.getInternal (ng:///AppModule/module.ngfactory.js:395)
      at injectionError (node_modules/@angular/core//bundles/core.umd.js:1238)
      at noProviderError (node_modules/@angular/core//bundles/core.umd.js:1276)
      at ReflectiveInjector_._throwOrNull (node_modules/@angular/core//bundles/core.umd.js:2777)
      at ReflectiveInjector_._getByKeyDefault (node_modules/@angular/core//bundles/core.umd.js:2816)
      at ReflectiveInjector_._getByKey (node_modules/@angular/core//bundles/core.umd.js:2748)
      at ReflectiveInjector_.get (node_modules/@angular/core//bundles/core.umd.js:2617)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:164)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:174)
      at AppModuleInjector.get (ng:///AppModule/module.ngfactory.js:219)
      at AppModuleInjector.getInternal (ng:///AppModule/module.ngfactory.js:395)
      at resolvePromise (zone.js:757)
      at resolvePromise (zone.js:728)
      at zone.js:805
      at ZoneDelegate.invokeTask (zone.js:414)
      at Object.onInvokeTask (node_modules/@angular/core//bundles/core.umd.js:4126)
      at ZoneDelegate.invokeTask (zone.js:413)
      at Zone.runTask (zone.js:181)
      at drainMicroTaskQueue (zone.js:574)
      at HTMLAnchorElement.ZoneTask.invoke (zone.js:480)
  </code></pre>
  
  <p>I am not finding any clue about the issue. Any help is much appreciated!.</p>
  
  <p>Service: </p>
  
  <pre><code>import * as firebase from 'firebase/app';
  import { AngularFireAuthModule, AngularFireAuth } from 'angularfire2/auth';
  import { Injectable } from '@angular/core';
  import { Http, Response } from '@angular/http';
  import { Observable } from 'rxjs/Observable'; 
  
  @Injectable()
  export class AdminService   {  
      private authUser:any;
      private authState:any;
      private loggedInUser:any;
      userLoggedin:boolean=false;
         constructor(public afAuth: AngularFireAuth) { 
               this.afAuth.authState.subscribe((auth) =&gt; {
                this.authState = auth;
                console.log(this.authState);
              });
      }
  
  
      login(loginEmail:string,loginPassword:string){
          this.afAuth.auth.signInWithEmailAndPassword(loginEmail,loginPassword)
          .catch(function(error){
              alert(" unable to login.Try again");
          });
      }
  }
  </code></pre>
  
  <p>Thank you</p>