Creates LXD container based build hosts

This provides the ways that deal with mutiple virtualized and containerized solutions such as Libvirt(KVM) and LXD. This uses MAAS for bare-metal provision(KVM machine using Libvirt), DHCP and DNS. This will also provide the ways to deal with muchltiple development environment such as development, stage and production.

A Vagrant plugin that allows management of containers using LXD.