Upgrade React Native 0.57.1 and Expo

Switching to Expo since it makes upgrades easier and is the default
starting point for React Native these days.

.gitignore

@@ -1,55 +1,8 @@
-# OSX
-#
-.DS_Store
-
-# Xcode
-#
-build/
-*.pbxuser
-!default.pbxuser
-*.mode1v3
-!default.mode1v3
-*.mode2v3
-!default.mode2v3
-*.perspectivev3
-!default.perspectivev3
-xcuserdata
-*.xccheckout
-*.moved-aside
-DerivedData
-*.hmap
-*.ipa
-*.xcuserstate
-project.xcworkspace
-
-# Android/IJ
-#
-*.iml
-.idea
-.gradle
-local.properties
-
-# node.js
-#
-node_modules/
-npm-debug.log
-
-# Config
-#
+node_modules/**/*
+.expo/*
+npm-debug.*
+*.jks
+*.p12
+*.key
+*.mobileprovision
 /config.js
-
-# BUCK
-buck-out/
-\.buckd/
-*.keystore
-
-# fastlane
-#
-# It is recommended to not store the screenshots in the git repo. Instead, use fastlane to re-generate the
-# screenshots whenever they are needed.
-# For more information about the recommended setup visit:
-# https://docs.fastlane.tools/best-practices/source-control/
-
-*/fastlane/report.xml
-*/fastlane/Preview.html
-*/fastlane/screenshots

.watchmanconfig

@@ -1 +1 @@
-{}
+{}

index.js → App.js

@@ -1,12 +1,12 @@
 import React, { Component } from 'react'
-import { AppRegistry } from 'react-native'
+import { AppRegistry, View } from 'react-native'
 import { Provider } from 'react-redux'
 import App from './src/containers/App'
 import configureStore from './src/store/configureStore'
 
 const store = configureStore()
 
-class Groceries extends Component {
+export default class Groceries extends Component {
   render() {
     return (
       <Provider store={store}>
@@ -15,5 +15,3 @@ class Groceries extends Component {
     )
   }
 }
-
-AppRegistry.registerComponent('Groceries', () => Groceries)

README.md

@@ -13,8 +13,8 @@ A simple grocery list app using React Native, Redux, Firebase, and Async Storage
 Built and tested with:
 
 * OS X / macOS
-* Node 7
-* Xcode 8
+* Node 10
+* Xcode 10
 * Android SDK
 
 A [Firebase](https://firebase.google.com) account is also needed. The security rules for the database must be set to public, since this app doesn't implement authentication. In the [Firebase Console](https://firebase.google.com/console/) under the Database section, Rules tab, change the rules to: