Update to Drupal 8.0.0-rc3. For more information, see https://www.drupal.org/node/2608078

core/core.libraries.yml

@@ -24,10 +24,10 @@ classList:
 
 ckeditor:
   remote: https://github.com/ckeditor/ckeditor-dev
-  version: "4.5.3"
+  version: "4.5.4"
   license:
     name: GNU-GPL-2.0-or-later
-    url: https://github.com/ckeditor/ckeditor-dev/blob/4.5.3/LICENSE.md
+    url: https://github.com/ckeditor/ckeditor-dev/blob/4.5.4/LICENSE.md
     gpl-compatible: true
   js:
     assets/vendor/ckeditor/ckeditor.js: { preprocess: false, minified: true }
@@ -145,6 +145,7 @@ drupal.date:
   dependencies:
     - core/drupal
     - core/modernizr
+    - core/jquery.once
     - core/jquery.ui.datepicker
 
 drupal.debounce: