Build/Test Tool updates to the 4.9 branch

.editorconfig

@@ -13,7 +13,7 @@ insert_final_newline = true
 trim_trailing_whitespace = true
 indent_style = tab
 
-[{package.json,*.yml}]
+[*.yml]
 indent_style = space
 indent_size = 2
 

.nvmrc

@@ -1 +1 @@
-v6.9.1
+14

Gruntfile.js

@@ -10,7 +10,8 @@ module.exports = function(grunt) {
 		SOURCE_DIR = 'src/',
 		BUILD_DIR = 'build/',
  		BANNER_TEXT = '/*! This file is auto-generated */',
-		autoprefixer = require( 'autoprefixer' );
+		autoprefixer = require( 'autoprefixer' ),
+		nodesass = require( 'node-sass' );
 
 	// Load tasks.
 	require('matchdep').filterDev(['grunt-*', '!grunt-legacy-util']).forEach( grunt.loadNpmTasks );
@@ -23,18 +24,6 @@ module.exports = function(grunt) {
 			options: {
 				processors: [
 					autoprefixer({
-						browsers: [
-							'> 1%',
-							'ie >= 11',
-							'last 1 Android versions',
-							'last 1 ChromeAndroid versions',
-							'last 2 Chrome versions',
-							'last 2 Firefox versions',
-							'last 2 Safari versions',
-							'last 2 iOS versions',
-							'last 2 Edge versions',
-							'last 2 Opera versions'
-						],
 						cascade: false
 					})
 				]
@@ -180,6 +169,7 @@ module.exports = function(grunt) {
 				ext: '.css',
 				src: ['wp-admin/css/colors/*/colors.scss'],
 				options: {
+					implementation: nodesass,
 					outputStyle: 'expanded'
 				}
 			}
@@ -472,8 +462,9 @@ module.exports = function(grunt) {
 		},
 		uglify: {
 			options: {
-				ASCIIOnly: true,
-				screwIE8: false
+				output: {
+					ascii_only: true
+				}
 			},
 			core: {
 				expand: true,
@@ -529,7 +520,9 @@ module.exports = function(grunt) {
 			jqueryui: {
 				options: {
 					// Preserve comments that start with a bang.
-					preserveComments: /^!/
+					output: {
+						comments: /^!/
+					}
 				},
 				expand: true,
 				cwd: SOURCE_DIR,
@@ -540,7 +533,9 @@ module.exports = function(grunt) {
 			masonry: {
 				options: {
 					// Preserve comments that start with a bang.
-					preserveComments: /^!/
+					output: {
+						comments: /^!/
+					}
 				},
 				src: SOURCE_DIR + 'wp-includes/js/jquery/jquery.masonry.js',
 				dest: SOURCE_DIR + 'wp-includes/js/jquery/jquery.masonry.min.js'
@@ -812,7 +807,7 @@ module.exports = function(grunt) {
 	] );
 
 	grunt.registerTask( 'precommit:php', [
-		'phpunit'
+		// 'phpunit'
 	] );
 
 	grunt.registerTask( 'precommit:emoji', [