chore(build): fix zone.js typings error

Author: davideast

.npmignore

@@ -1 +1,2 @@
 *.spec.*
+bundles/test.umd.js

src/core/angularfire2.ts

@@ -4,6 +4,7 @@ import { Injectable, InjectionToken, OpaqueToken, NgModule } from '@angular/core
 import { Subscription } from 'rxjs/Subscription';
 import { Scheduler } from 'rxjs/Scheduler';
 import { queue } from 'rxjs/scheduler/queue';
+import 'zone.js';
 
 export interface FirebaseAppConfig {
   apiKey?: string;

src/core/index.ts

@@ -1 +1 @@
-export * from './index.api';
+export * from './public_api';