Purgecss and @addyosmani critical shouldn't be options for Nuxt.
<!--cmty--><!--cmty_prevent_hook--><div align="right"><sub><em>This feature request is available on <a href="https://nuxtjs.cmty.io">Nuxt.js</a> community (<a href="https://nuxtjs.cmty.io/nuxt/nuxt.js/issues/c2438">#c2438</a>)</em></sub></div>