Let Jekyll build your (lib)Sass and (lib)SCSS! A Sass converter for Jekyll that depends on libsass via the new sassc gem, as Ruby Sass (i.e. the sass gem) is deprecated and will reach end-of-life in March of 2019.
Add this line to your application's Gemfile:
gem "jekyll-sass-converter", :git =>
"https://github.com/searls/jekyll-sassc-converter.git"
This will override the official jekyll-sass-converter.