Vagrantfile in image_optim-0.26.3 vs Vagrantfile in image_optim-0.26.4

@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 Vagrant.configure('2') do |config|
   config.vm.box = 'ubuntu/precise64'
 
   config.vm.provision 'shell', :inline => <<-SH
     set -e