Install GitLab Runner Docker Cleanup

See GitLab Runner Docker Cleanup, current disk space:

df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.9G     0  7.9G   0% /dev
tmpfs           1.6G   65M  1.6G   4% /run
/dev/xvda2       77G   68G  4.5G  94% /
tmpfs           7.9G     0  7.9G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
tmpfs           1.6G     0  1.6G   0% /run/user/1001