After a while of messing around with the free / demo version of Ansible Tower I thought that this could also be done with free tools. With some help from the internet and as an IT consultant I found the way forward.
As we all known Ansible is for free and is a package in the Ubuntu repository. Ansible Tower is a frontend for Ansible that will provide scheduler and a fancy webfrontend.
Rundeck is a job scheduler and runbook administration that is for free and also has a fancy webfrontend.
So for the poor man's solution we are going to use the best of both worlds.