home.ts

import { AngularFireAuth } from 'angularfire2/auth';
import * as firebase from 'firebase/app';
...

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  user;

  constructor(public navCtrl: NavController,
    public twitterConnect: TwitterConnect,
    public afAuth: AngularFireAuth,
    public platform: Platform) {
  }
  ...
}