instead of Ubuntu-18.04. This fixes a crash when stress-testing the
metrics HTTP server. We think it was due to gcc-7.4.0 miscompiling
something. The new distro/version gives us gcc-8.3.0, but with the same
old glibc-2.28 we need on Raspbian.
We're moving from very slow QEMU-virtualised builds to very fast ones
based on cross toolchains.
- refactor jobs; add checksums to release note
- build and publish Docker images with ARM/ARM64 binaries
* Linux AMD64 binary distribution
The builds are reproducible, as long as our base Docker Hub image
remains available.
tl;dr: `make dist`
* use UTC dates