* Better config test
Previously, when using the config test option `-test`, we quit fairly
earlier in the process and would not catch a variety of additional
parsing errors (such as lighthouse IP addresses, local_range, the new
check to make sure static hosts are in the certificate's subnet, etc).
* run config test as part of smoke test
* don't need privileges for configtest
Co-authored-by: Nathan Brown <nate@slack-corp.com>
This change adds a new Github Action, a 3 node smoke test. It starts
three docker containers (one lighthouse and two standard nodes) and
tests that they can all ping each other. This should hopefully detect
any basic runtime failures in PRs.