* Migrate from the internal Drone server using a GitHub Workflow
to perform the multi-arch container image build
* Use self-hosted GitHub runners on ARM64 to perform the ARM64
build step faster that QEMU/KVM emulation
* Mandate approval for all workflow runs from outside contributors
since the builds use push credentials and partially run internally
* Use our own infra to perform image builds and push images. Provides
future options for publishing images to multiple image registries and
for multiple architectures, while keeping push permissions in-house
* Remove Travis ability to push to Quay
* Consider splitting repo and also enabling Quay automated builds
* Update base image from alpine:3.6 to alpine:3.9
* Automatically publish dnsmasq image on merge to a branch
named "dnsmasq". Similar to how matchbox is automatically
published from master. Set the version based on git SHA
* Add ipxe.efi to dnsmasq image's /var/lib/tftpboot directory
* Add initrd kernel argument respected only by UEFI
https://github.com/coreos/bugs/issues/1239
* Improve network-setup docs and scripts to cover UEFI clients
and to support launching UEFI QEMU/KVM clusters locally
* Reduce references to grub.efi flow, its not a happy path
* Add grub.efi to get-tftp-files script. This matches prior
dnsmasq images, but was not part of a repeatable build
* Switch rkt run examples to pull from quay.io
* Remove script using acbuild to create ACIs
