We need to set Ubuntu jobs to non-voting again since Tempest has stopped working with python2 now that some modules are not installed. I think the issue should be solved by just porting Tempest (when installed from source) to use python3.
This reverts commit edd7558ee2ab23539cd14da2e66293a6d24f5885.
Change-Id: I21b4128176372fdfb33f2ef6028d2bf0c59e709a
64dda8ac65