docs(badges): add node version badge

README.md

@@ -7,6 +7,7 @@
 [![Bountysource](https://www.bountysource.com/badge/team?team_id=955&style=bounties_received)](https://www.bountysource.com/teams/sequelize/issues?utm_source=Sequelize&utm_medium=shield&utm_campaign=bounties_received)
 [![Bountysource](https://www.bountysource.com/badge/team?team_id=955&style=bounties_received)](https://www.bountysource.com/teams/sequelize/issues?utm_source=Sequelize&utm_medium=shield&utm_campaign=bounties_received)
 [![Slack Status](http://sequelize-slack.herokuapp.com/badge.svg)](http://sequelize-slack.herokuapp.com/)
 [![Slack Status](http://sequelize-slack.herokuapp.com/badge.svg)](http://sequelize-slack.herokuapp.com/)
 [![npm downloads](https://img.shields.io/npm/dm/sequelize.svg?maxAge=2592000)](https://www.npmjs.com/package/sequelize)
 [![npm downloads](https://img.shields.io/npm/dm/sequelize.svg?maxAge=2592000)](https://www.npmjs.com/package/sequelize)
+![node](https://img.shields.io/node/v/sequelize.svg)
 [![License](https://img.shields.io/npm/l/sequelize.svg?maxAge=2592000?style=plastic)](https://github.com/sequelize/sequelize/blob/master/LICENSE)
 [![License](https://img.shields.io/npm/l/sequelize.svg?maxAge=2592000?style=plastic)](https://github.com/sequelize/sequelize/blob/master/LICENSE)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)