Extra styles.css in build

When building my Jekyll project, I noticed a heavy styles.css being included in my assets/css folder despite having no style file in my scss folder or Gruntfile.

It turns out this is due to the Github Pages gem fallback to jekyll-theme-primer when I removed the theme: minima from the _config.yml

To fix this, make sure to set theme to null in the config instead.

Issue on Github: #7478