Adding a cask for Vagrant v1.4.3.

Squashed commit of the following:

commit e76734d02d096d1a5acf8288d7f12c6cae5436f3
Author: Ben Kreeger <ben@kree.gr>
Date:   Wed Mar 19 12:22:48 2014 -0500

    Ensuring name is correct.

commit 25f3a557f751c037934d35421990fa00c7571543
Author: Ben Kreeger <ben@kree.gr>
Date:   Wed Mar 19 12:21:04 2014 -0500

    Adding a cask for Vagrant v1.4.3.

Casks/vagrant143.rb

@@ -0,0 +1,8 @@
+class Vagrant143 < Cask
+  url 'https://dl.bintray.com/mitchellh/vagrant/Vagrant-1.4.3.dmg'
+  homepage 'http://www.vagrantup.com'
+  version '1.4.3'
+  sha1 '78d20fbe44704d91b7958af57308eb0fde147ed4'
+  install 'Vagrant.pkg'
+  uninstall :script => 'uninstall.tool', :input => %w[Yes]
+end