This version solves a security issue:
https://ckeditor.com/cke4/release/CKEditor-4.11.0
Note this version adds a `ckeditor/samples` folder, which is
automatically added to the application's assets manifest even if we
remove all CKEditor references in our application. One of the files in
that folder makes ExecJS raise a syntax error, causing every page to
raise a 500 error.