Use Github actions for integration tests against Vagrant-libvirt (#1091)

Allows to spin up vagrant boxes via vagrant-libvirt in CI replacing the 
need for vagrant-libvirt-qa to be executed separately before/after 
releases.

* Adds a github integration tests workflow
* Installs the needed toolset in separate groups for easier tracking
* Add Vagrantfile definitions for the first simple test cases in tests/ 
  using tinycore linux, using the installed master version these boxes 
  are spun up and destroyed via a test matrix.

Should help reduce effort for new maintainers to help with #1069

tests/simple_provision_shell/Vagrantfile

@@ -0,0 +1,9 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+Vagrant.configure("2") do |config|
+  config.vm.box = "infernix/tinycore"
+  config.ssh.shell = "/bin/sh"
+  config.vm.synced_folder ".", "/vagrant", disabled: true
+  config.vm.provision "shell", inline: "echo Hello, World", privileged: false
+end