Override rnpm defaults to simplify ios/android installations.

[michalchudziak]

We should be able to hide linking pods and adding maven repo in android under the react-native link command.

See following files for reference:

https://github.com/Microsoft/mobile-center-sdk-react-native/blob/develop/mobile-center-analytics/package.json#L47

https://github.com/Microsoft/mobile-center-sdk-react-native/blob/develop/mobile-center-analytics/scripts/postlink.js