Docker builds of displaz

Motivation

Check the displaz builds and tests for a variety of Linux flavours.

User Guide

docker build docker/ubuntu_18_04
docker image prune -af

Options

REPO build from specified from git repository
MIRROR use Ubuntu package mirror
- Australia: http://au.archive.ubuntu.com/ubuntu/

For example:

docker build docker/ubuntu_18_04 --build-arg MIRROR=http://au.archive.ubuntu.com/ubuntu/

Notes

Ubuntu 12.04 Precise does not support C++11 required for displaz