[react-native] wrapped AsyncStorage with JSON support

storage.js

import { AsyncStorage } from 'react-native';

const JSONAsyncStorage = Object.assign({}, AsyncStorage, {
	getItem() {
		return AsyncStorage.getItem.apply(null, arguments).then((res) => JSON.parse(res));
	},
	setItem(key, value) {
		return AsyncStorage.setItem(key, JSON.stringify(value))
	}
});

export default JSONAsyncStorage;