Clean up docker containers and images

docker-hard-clean.sh

# Frees up a lot of disk space by removing almost everything from the docker cache.

# Get rid of all unnamed containers.
sudo docker ps -a | grep -v ":" | grep -v "ID" | awk '{ print $1 }' | sort | uniq | xargs sudo docker rm

# Get rid of all unnamed images.
sudo docker images | grep "^<none>" | awk '{ print $3 }' | xargs sudo docker rmi