Merge branch 'fix/gutenberg-clean-before-build' into fix/missing-new-files

Author: desrosj

Gruntfile.js

@@ -51,6 +51,7 @@ module.exports = function(grunt) {
 		gutenbergFiles = [
 			'wp-includes/js/dist',
 			'wp-includes/css/dist',
+			'wp-includes/images/icon-library',
 			// Old location kept temporarily to ensure they are cleaned up.
 			'wp-includes/icons',
 		],
@@ -2157,6 +2158,7 @@ module.exports = function(grunt) {
 	} );
 
 	grunt.registerTask( 'build:gutenberg', [
+		'clean:gutenberg',
 		'copy:gutenberg-php',
 		'routes:setup',
 		'copy:routes',