Error while generating docs guides

[Comandeer]

During upgrade ckeditor-docs to Umberto, path to guides was changed. However this change was not propagated to SDK, resulting in following error:

[ { Error: ENOENT: no such file or directory, lstat '/Users/comandeer/repos/ckeditor/ckeditor-sdk/docs/guides'
      at Error (native)
    errno: -2,
    code: 'ENOENT',
    syscall: 'lstat',
    path: '/Users/comandeer/repos/ckeditor/ckeditor-sdk/docs/guides' } ]