These instructions will create a virtual machine in Vagrant, which runs the Numbas LTI provider proxied through nginx. If you want to run on a real machine, skip the first couple of steps to do with Vagrant. I used Ubuntu 16.04 - the process of installing packages will be different on different versions or different distributions.
I set up Vagrant to forward port 443 on the host machine to port 443 on the VM. I think this might only work on Windows. I'm not sure how to get it running on a different port - I had problems with the nginx proxy.
Create a directory for the vagrant VM: