Grunt: Replace custom rimraf-based clean task with grunt-contrib's clean task

build/tasks/build.js

@@ -181,10 +181,6 @@ grunt.registerTask( "copy_themes", function() {
 	});
 });
 
-grunt.registerTask( "clean", function() {
-	require( "rimraf" ).sync( "dist" );
-});
-
 grunt.registerTask( "authors", function() {
 	var done = this.async();
 

grunt.js

@@ -81,6 +81,7 @@ uiFiles.forEach(function( file ) {
 });
 
 // grunt plugins
+grunt.loadNpmTasks( "grunt-contrib" );
 grunt.loadNpmTasks( "grunt-css" );
 grunt.loadNpmTasks( "grunt-html" );
 grunt.loadNpmTasks( "grunt-compare-size" );
@@ -131,6 +132,7 @@ grunt.initConfig({
 		bannerCSS: createBanner( cssFiles )
 	},
 	compare_size: compareFiles,
+	clean: ["dist"],
 	concat: {
 		ui: {
 			src: [ "<banner:meta.bannerAll>", stripBanner( uiFiles ) ],

package.json

@@ -27,12 +27,12 @@
   "dependencies": {},
   "devDependencies": {
     "grunt": "0.3.9",
+    "grunt-contrib": "0.0.7",
     "grunt-css": "0.2.0",
     "grunt-compare-size": "0.1.4",
     "grunt-html": "0.1.1",
     "grunt-junit": "0.1.4",
     "request": "2.9.153",
-    "rimraf": "2.0.1",
     "testswarm": "0.2.2"
   },
   "keywords": []