Use --cache-from in Drone CI

[marcinjosinski]

1. Deploy a production-ready docker registry on HAL.
2. resolve --cache-from conflicts with multi-stage builds
3. Reorganize steps in drone.yml:
   • build
   • test
   • push
   • release (only for master)

Links:

• https://andrewlock.net/caching-docker-layers-on-serverless-build-hosts-with-multi-stage-builds---target,-and---cache-from/
• https://medium.com/@gajus/making-docker-in-docker-builds-x2-faster-using-docker-cache-from-option-c01febd8ef84
• https://gitlab.com/snippets/185782
• https://laszlo.cloud/how-using-cache-from-can-speed-up-your-docker-builds-in-droneci