v0.1.7: Added the `cloudflare_threat_control` LWRP

Based off an initial work by Adrien Siebert (https://github.com/asiebert)

This LWRP allows to manage Cloudflare's threat control services

Also adapted the Vagrantfile to make it possible to use Chef-Zero instead of solo.
However, I'll need to switch to Test-KItchen pretty soon as the vagrant-chef-zero
plugin is going to be deprecated pretty soon.