Refactor Vagrantfile to allow other providers
Refactor Vagrantfile to allow other providers

This patch includes the parallels provider as an example and
sets two top variables to control over the RAM and CPUs.

Change-Id: Ib3379721990863259cc9095a715ae663f9a8c5ca

celebdor/kuryr-libnetwork,midonet/kuryr,openstack/kuryr,celebdor/kuryr,openstack/kuryr,celebdor/kuryr-libnetwork,midonet/kuryr,celebdor/kuryr,midonet/kuryr,celebdor/kuryr-libnetwork