`vagrant down` is now `vagrant destroy`

bin/vagrant-destroy

@@ -22,6 +22,6 @@ Destroys the vagrant environment.
 EOS
 
   run do |command|
-    Vagrant::Commands.execute(:down)
+    Vagrant::Commands.execute(:destroy)
   end
 end

lib/vagrant/commands.rb

@@ -29,13 +29,13 @@ module Vagrant
       end
     end
 
-    # Tear down a vagrant instance. This not only shuts down the instance
+    # Destroys a vagrant instance. This not only shuts down the instance
     # (if its running), but also deletes it from the system, including the
     # hard disks associated with it.
     #
     # This command requires that an instance already be brought up with
     # `vagrant up`.
-    def down
+    def destroy
       env.require_persisted_vm
       env.vm.destroy
     end