infra - Need automated test of infra code for slave set-up

Many infra changes infra repo (buildtest module, cloudera module,...) can impact test results, but infra test jobs do not test viability of slave test environment.

We need dev/test nodes for slaves, and perhaps zuul and jenkins to properly test infra before impacting the production environment. Like install testing, this has restrictions, since puppet runs as root. So this can not be run in unsupervised check testing.

Also these test machines can not be updated from "production" puppet configuration with time-based runs, but must be tested with puppet apply instead.

Should be implemented after infra-upgrade-puppet is implemented.