Make some fixes to get tests passing on Ruby 1.8.7

lib/vagrant/action/warden.rb

@@ -68,6 +68,10 @@ module Vagrant
       def finalize_action(action, env)
         klass, args, block = action
 
+        # Default the arguments to an empty array. Otherwise in Ruby 1.8
+        # a `nil` args will actually pass `nil` into the class.
+        args ||= []
+
         if klass.is_a?(Class)
           # A action klass which is to be instantiated with the
           # app, env, and any arguments given

lib/vagrant/environment.rb

@@ -175,7 +175,7 @@ module Vagrant
     #
     # @return [Action::Runner]
     def action_runner
-      @action_runner ||= Action::Runner.new(action_registry) do |env|
+      @action_runner ||= Action::Runner.new(action_registry) do
         {
           :action_runner  => action_runner,
           :box_collection => boxes,