🔧 Fix node version info

Author: Michal Vlasák

README.md

@@ -5,6 +5,7 @@
 ![Cosmas](https://i.imgur.com/EFe3wOa.png)
 
 [![Build Status](https://img.shields.io/travis/com/AckeeCZ/cosmas/master.svg?style=flat-square)](https://travis-ci.com/AckeeCZ/cosmas)
+[![Node Version](https://img.shields.io/node/v/cosmas)](https://www.npmjs.com/package/cosmas)
 [![Npm](https://img.shields.io/npm/v/cosmas.svg?style=flat-square)](https://www.npmjs.com/package/cosmas)
 [![License](https://img.shields.io/github/license/AckeeCZ/cosmas.svg?style=flat-square)](https://github.com/AckeeCZ/cosmas/blob/master/LICENSE)
 [![Coverage Status](https://img.shields.io/coveralls/github/AckeeCZ/cosmas.svg?style=flat-square)](https://coveralls.io/github/AckeeCZ/cosmas?branch=master)

package.json

@@ -23,7 +23,7 @@
   "author": "Michal Vlasák <michal.vlasak@ackee.cz>",
   "license": "ISC",
   "engines": {
-    "node": "^6.14.3"
+    "node": ">=6"
   },
   "repository": {
     "type": "git",