Fix libvirt dependency

[michalgritzbach]

Why are you introducing these changes? (Problem description, related links)

Foreman and Foreman's dev setup document assumes that libvirt is installed in the system. Without libvirt, Foreman's test suite fails to run (specifically https://github.com/theforeman/foreman/blob/develop/test/integration/host_js_test.rb#L4 - the require immediately stops the suite).

What are the changes introduced in this pull request?

• adds libvirt-devel to foreman_development_packages
• changes bundle install command in foreman_development role to include libvirt gem group

How to test this pull request

Steps to reproduce:

• libvirt-devel is present, fog-libvirt (+ ruby-libvirt) are installed on a fresh system

Checklist

• Tests added/updated (if applicable)
• Documentation updated (if applicable)

[evgeni]

One could argue those tests could skip if there is no libvirt, instead of failing, but I am not in an arguing mood ;)

[evgeni]

No package libvirt-devel available.

I think on CentOS you need to enable crb repo for this.

[ares]

Wouldn't it be nice if I could get dev environment ready to hack on any part of the Foreman? Perhaps forge can be extended with features-like concept if needed. While we can also start skipping tests, I'd still like to have a standard way to deploy dev environment for libvirt integration and more feature in future.