Adding same changes to other Vagrantfiles.

vagrant/base/devstack/Vagrantfile

+VAGRANTFILE_API_VERSION = "2"
+Vagrant.require_version ">= 1.3.4"
+
 MEMORY = 2048
 CPU_COUNT = 2
 
@@ -14,7 +17,7 @@ if ENV['VAGRANT_MOUNT_BASE']
 end
 
 
-Vagrant.configure("2") do |config|
+Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   # Creates a devstack from a base Ubuntu 12.04 image
   config.vm.box     = "precise64"

vagrant/base/fullstack/Vagrantfile

+VAGRANTFILE_API_VERSION = "2"
+Vagrant.require_version ">= 1.3.4"
+
 MEMORY = 2048
 CPU_COUNT = 2
 
-Vagrant.configure("2") do |config|
+Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   config.vm.box     = "precise64"
   config.vm.box_url = "http://files.vagrantup.com/precise64.box"
 

vagrant/release/fullstack/Vagrantfile

+VAGRANTFILE_API_VERSION = "2"
+Vagrant.require_version ">= 1.3.4"
+
 MEMORY = 2048
 CPU_COUNT = 2
 
-Vagrant.configure("2") do |config|
+Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   # Creates an edX fullstack VM from an official release
   config.vm.box     = "gugelhupf"