Add ubuntu 18.04 support

[danquack]

Pull Request (PR) description

I know theres no vagrant image yet (created ticket: see below), but i figured it might be nice to at least run the tests in travis. Not sure if you want to claim that as "supported", but I figured it was a start.

https://tickets.puppetlabs.com/browse/IMAGES-913

This Pull Request (PR) fixes the following issues

Partially fixes #399
This issue should probably stay open until acceptance tests are added, but this is a start to certifying with 18.04.

[ekohl]

We manage .travis.yml via .sync.yml with modulesync. Could you update that as well so we don't overwrite it on the next update?

[bastelfreak]

@danquack FYI there are already acceptance tests: https://github.com/voxpupuli/puppet-python/tree/master/spec/acceptance

As soon as you add ubuntu 18.04 to .sync.yml we can merge this.

[danquack]

@bastelfreak, I can most certainly add that to the sync file. What I was bringing up, was there’s no nodeset for Ubuntu 18, although this does run it through Travis.

[bastelfreak]

A nodeset is not required anymore. They are generated by BEAKER_setfile=ubuntu1804-64{hypervisor=docker}.

[danquack]

Is it something worth removing all together in a separate PR?

[bastelfreak]

Our nodesets come from https://github.com/voxpupuli/modulesync_config/tree/master/moduleroot/spec/acceptance/nodesets. I did not test the generator for anything except docker nodesets. If you want you can open an issue on https://github.com/voxpupuli/modulesync_config to discuss the removal. We already purged all the docker nodesets.