Automaticly purge build tags that were cut by Jenkins

gistfile1.sh

# Purge old tags
tag_limit=8
tag_current=`git tag -n |grep -i "jenkins-${JOB_NAME}" | wc -l`
if [ $tag_limit -lt $tag_current ]; then
        tag_difference=`expr $tag_current - $tag_limit `
        git tag |grep -i "jenkins-${JOB_NAME}" | head -$tag_difference | xargs git push --delete origin
        git tag |grep -i "jenkins-${JOB_NAME}" | head -$tag_difference | xargs git tag -d
fi 

# Create tag 
git push --tags