docker: Update to Ubuntu 18.04 LTS
[petitboot] / docker /
drwxr-xr-x   ..
-rw-r--r-- 411 Dockerfile.builder
-rw-r--r-- 831 README.md
-rwxr-xr-x 2914 build-builder
-rwxr-xr-x 2677 build-pb
-rw-r--r-- 852 builder-include