Dockerfile: set apt-get's config to be non-interactive

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>
Dockerfile: add apt-utils

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>
Dockerfile: upgrade build-tools and API

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>
README.md: note versions installed

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>