ARM64 build and multi-arch Docker image

[ahjohannessen]

It would be nice to get an arm build in order to avoid messages like:

WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested

in docker.

_DEV-79

[alexeyzimarev]

That's what #12 supposed to fix, I need to wrap it up.