Not compatible with css-loader@3.0.0

I have `localIdentName` set to `'[path]___[name]__[local]___[hash:base64:5]'` in the `css-loader`, but as of 3.0.0 this generates a name (in css-loader) where slashes and dots aren't replaced with dashes but rather escaped.

That's a bit uglier to read now (anyway, they aren't really meant for humans) -- but the main problem is that this plugin now generates invalid `className` values because it's using the old logic.

Example:

className: `rb-client-js-modules-landing-___Landing-module__landing-page-card___kz6iY`
css: `.rb\/client\/js\/modules\/landing\/___Landing\.module__landing-page-card___kz6iY`