clean the old rootfs archives out of this repo

git clone --mirror [email protected]:greyltc/docker-archlinux.git
# now check this page to find the latest version number of bfg https://rtyley.github.io/bfg-repo-cleaner/
BFG_VER=1.12.8
curl http://repo1.maven.org/maven2/com/madgag/bfg/$BFG_VER/bfg-$BFG_VER.jar > bfg.jar
java -jar bfg.jar --strip-blobs-bigger-than 20M docker-archlinux.git
cd docker-archlinux.git
git reflog expire --expire=now --all && git gc --prune=now --aggressive
git push --force --tags origin 'refs/heads/*'