Remove `files/` in front of the certs path

Contrary to what is expected, in that case Ansible does not look in the
good place.
crossplatform way to check the version of rabbitmq
Added redhat install script

Conflicts:
	tasks/install/redhat.yml
Avoid always vagrant with Centos
Merge branch 'pr_14'. Add support for Redhat
Update the test part to show how to change the vagrant VM
Allow the test to run with TLS on
Update the CHANGELOG