Installation steps

1. Go to https://console.firebase.google.com and create a project.
2. On project overview choose Add Firebase to your web app.
3. Copy given config into Config.js.
4. Enable e-mail authentication and facebook authentication from Authentication tab in Firebase console.
5. Follow steps in https://docs.expo.io/versions/latest/sdk/facebook.
6. Follow steps in https://medium.com/nycdev/create-a-react-native-app-with-google-map-using-expo-io-68041252023d including add google maps to IOS section.
7. Register your push notification handler endpoints in Notifications.js and Screen/Setting.js with info provided in https://docs.expo.io/versions/latest/guides/push-notifications.