message: added information about version 4.x
diff: +# xero-node
  +
  +## Looking for OAuth 2.0 support?
  +
  [![npm version](https://badge.fury.io/js/xero-node.svg)](https://badge.fury.io/js/xero-node)
  +
  +xero-node with OAuth 2.0 support is available on npm with beta tag removed.
  +
  +Examples and code is located in the [oauth2 branch](https://github.com/XeroAPI/xero-node/tree/oauth2) (will be promoted to master soon). Please submit pull requests to the `oauth2` branch for review and submit issues for us to review.
  +
  +> Version 4 is a complete rewrite of xero-node and not a continuation of version 3.
  +> All OAuth 2.0 SDKs built by Xero will be generated from our [OpenAPI 3.0](https://github.com/XeroAPI/Xero-OpenAPI) specifications.
  +> We still welcome your feedbacks and PRs - please see [guidelines around contributing](https://github.com/XeroAPI/xero-node/blob/oauth2/CONTRIBUTING.md).
  +> A [kitchen sync app](https://github.com/XeroAPI/xero-node-oauth2-app) is available that demonstrates interacting with each endpoint.
  +
  +## Looking for OAuth 1.0a support?
  +
  +
  +[![npm package](https://img.shields.io/badge/npm%20package-3.1.1-blue.svg)](https://www.npmjs.com/package/xero-node/v/3.1.1)
  +
  [![CircleCI](https://circleci.com/gh/XeroAPI/xero-node/tree/master.svg?style=svg)](https://circleci.com/gh/XeroAPI/xero-node/tree/master)
  -# xero-node
  +xero-node 3.xx with OAuth 1.0a support is available on npm.
  NodeJS Client for the [Xero API](http://developer.xero.com). Works with ES5, ES6+ and TypeScript.
  