add basic test structure--still a WIP. Add test for setting domain name

lib/vagrant-libvirt/action/set_name_of_domain.rb

@@ -36,6 +36,7 @@ module VagrantPlugins
 
         # build domain name
         # avoids `domain about to create is already taken`
+        # parsable and sortable by epoch time
         # @example
         #   development-centos-6-chef-11_1404488971_3b7a569e2fd7c554b852
         # @return [String] libvirt domain name

spec/support/environment_helper.rb

@@ -3,7 +3,7 @@ require "pathname"
 
 class EnvironmentHelper
 
-  attr_writer :default_prefix
+  attr_writer :default_prefix, :domain_name
 
   def [](value)
     self.send(value.to_sym)