If you're using an unsupported 3rd party gem on a Jekyll site you are hosting with GitHub pages…

deploy-jekyll.sh

rm -rf _site
bundle exec jekyll build
cd _site
git init
git remote add origin https://github.com/[username]/[repo_name].git
git checkout -b gh-pages
git add -A
git commit -m "update site"
git push -f origin gh-pages
cd ../
rm -rf _site