Build: remove async and spawnback dependencies

Use async-await, for-of, and cp.spawn directly.

Gruntfile.js

@@ -2,6 +2,12 @@
 
 module.exports = function( grunt ) {
 	grunt.initConfig( {
+		xmllint: {
+			all: [
+				"fixture/entries/**",
+				"entries2html.xsl"
+			]
+		},
 		"build-posts": {
 			page: "fixture/pages/**"
 		},
@@ -21,5 +27,6 @@ module.exports = function( grunt ) {
 
 	grunt.loadTasks( "tasks" );
 
+	grunt.registerTask( "lint", [ "xmllint" ] );
 	grunt.registerTask( "build", [ "build-posts", "build-resources", "build-xml-entries" ] );
 };

lib/util.js

@@ -1,7 +1,6 @@
 "use strict";
 
 const fs = require( "fs" );
-const async = require( "async" );
 const marked = require( "marked" );
 
 function htmlEscape( text ) {
@@ -69,23 +68,13 @@ function parseMarkdown( src, options ) {
 	return marked.parser( tokens );
 }
 
-function eachFile( files, stepFn, complete ) {
-	var count = 0;
-
-	async.forEachSeries( files, function( fileName, fileDone ) {
+async function eachFile( files, stepFn ) {
+	for ( const fileName of files ) {
 		if ( !fs.statSync( fileName ).isFile() ) {
-			return fileDone();
-		}
-
-		count++;
-		stepFn( fileName, fileDone );
-	}, function( error ) {
-		if ( error ) {
-			return complete( error );
+			continue;
 		}
-
-		complete( null, count );
-	} );
+		await stepFn( fileName );
+	}
 }
 
 exports.htmlEscape = htmlEscape;

package.json

@@ -20,19 +20,18 @@
     }
   ],
   "dependencies": {
-    "async": "^3.2.0",
     "cheerio": "^1.0.0-rc.12",
     "grunt-check-modules": "^1.1.0",
     "gilded-wordpress": "1.0.6",
     "he": "^1.2.0",
     "highlight.js": "^10.7.2",
     "marked": "^4.0.0",
-    "spawnback": "^1.0.1",
     "which": "^4.0.0",
     "wordpress": "^1.4.1"
   },
   "scripts": {
     "test": "eslint . && qunit test/*.js",
+    "lint-example": "grunt lint",
     "build-example": "grunt build"
   },
   "devDependencies": {