remove node 6

install/package.json

@@ -122,7 +122,6 @@
         "spider-detector": "1.0.18",
         "toobusy-js": "^0.5.1",
         "uglify-es": "^3.3.9",
-        "util.promisify": "1.0.0",
         "validator": "10.9.0",
         "winston": "3.1.0",
         "xml": "^1.0.1",
@@ -150,7 +149,7 @@
         "url": "https://github.com/NodeBB/NodeBB/issues"
     },
     "engines": {
-        "node": ">=6"
+        "node": ">=8"
     },
     "maintainers": [
         {

src/promisify.js

@@ -1,8 +1,5 @@
 'use strict';
 
-// remove once node 6 support is removed
-require('util.promisify/shim')();
-
 var util = require('util');
 var _ = require('lodash');