title: Angular Service worker with FCM push notification
body: <p>In my web app(using Angular4) I am using <code>"@angular/service-worker": "^1.0.0-beta.16"</code> for generating service worker and also using <code>firebase-messaging-sw.js</code> for FCM push notification, angular/service-worker creates <code>worker-basic.min.js</code> only in production build. Now, how to use these 2 service-workers together??</p>