Creates php5 role for ansible.

Most common packages out there are enabled by default, it is possible to
use a `php_packages` variable in order to define your own set of
packages to be installed.

Package installation already supports multiple OS, but only
Debian-family are defined as I don't ~~give a fuck~~ known what are the
right package names in RedHat-family anymore.

`Vagrantfile` is also updated to run the `test.yml` playbook which aims
to contain all the roles available, as the name suggest its purpose.

You may be wondering what the *hwr* prefix on internal variables means.
It stands for "hyper-wave relay", from Asimov's Foundation series. Not
that I dislike the "Ansible" work neither Ursula Le Guin novels, but
Asimov is most dear to me.