Error while adding simple-ruler plugin in ckeditor4

Question

I am unable add simple-ruler plugin to my ckeditor. Initially it was giving the below error: "ReferenceError: require is not defined"

So, I added this to my index.html file: <script src="https://requirejs.org/docs/release/2.3.5/minified/require.js > </ script>

Now I am getting another error: Uncaught Error: Module name "nouislider" has not been loaded yet for context: _. Use require([]) http://requirejs.org/docs/errors.html#notloaded

I have gone through some links which have discussed the same issue: https://github.com/lovata2/ckeditor-ruler/issues/5 but still couldn't make it work.

I don't know how to make this plugin work. Can someone please share some solution which might help..