Buildbot infrastructure upgrade

[Petr Štetiar]

Hi,

I would like to let you know, that we've prepared upgrade of the Buildbot
based infrastructure and there is a plan to make those changes alive. 

We would like to bump master and workers in the upcoming days to the latest
and greatest Buildbot stable release 3.0.0 (current is 0.8.12) with Debian 10
using gcc-8 (current is Debian 9 with gcc-6) compiler on the host. I'll keep
you posted.

Cheers,

Petr