chore(npm): update CKEditor to version 4.15.1

UI/WebServerResources/js/vendor/ckeditor/build-config.js

@@ -13,10 +13,10 @@
  * (1) https://ckeditor.com/cke4/builder
  *     Visit online builder to build CKEditor from scratch.
  *
- * (2) https://ckeditor.com/cke4/builder/c46c1afcec832ab957dafc25b60c4ab2
+ * (2) https://ckeditor.com/cke4/builder/ee9c7686fb78e4800d3347e1450be0a2
  *     Visit online builder to build CKEditor, starting with the same setup as before.
  *
- * (3) https://ckeditor.com/cke4/builder/download/c46c1afcec832ab957dafc25b60c4ab2
+ * (3) https://ckeditor.com/cke4/builder/download/ee9c7686fb78e4800d3347e1450be0a2
  *     Straight download link to the latest version of CKEditor (Optimized) with the same setup as before.
  *
  * NOTE:
@@ -39,6 +39,7 @@ var CKBUILDER_CONFIG = {
 		'.jshintrc',
 		'.mailmap',
 		'.npm',
+		'.nvmrc',
 		'.travis.yml',
 		'README.md',
 		'bender-err.log',
@@ -49,6 +50,7 @@ var CKBUILDER_CONFIG = {
 		'gruntfile.js',
 		'less',
 		'node_modules',
+		'package-lock.json',
 		'package.json',
 		'tests'
 	],