Upgrade to React Native 0.60

[alexsegura]

Fixes #206
Fixes #174
Fixes #173

TODO

• Remove ios/Pods from version control
• Make sure file upload works (rn-fetch-blob)
• Cleanup dependencies in android/build.gradle & android/app/build.gradle (use auto-linking)
• Make sure keeping screen awake works (react-native-keep-awake)
• Use PushNotificationIOS from react-native-community
• Make sure notifications work

[alexsegura]

[!] use_native_modules! skipped the react-native dependency 'react-native-open-settings'. No podspec file was found.
    - Check to see if there is an updated version that contains the necessary podspec file
    - Contact the library maintainers or send them a PR to add a podspec. The react-native-webview podspec is a
    good example of a package.json driven podspec. See
    https://github.com/react-native-community/react-native-webview/blob/master/react-native-webview.podspec
    - If necessary, you can disable autolinking for the dependency and link it manually. See
    https://github.com/react-native-community/cli/blob/master/docs/autolinking.md#how-can-i-disable-autolinking-for-unsupported-library

lunarmayor/react-native-open-settings#21