Guardfile in secure_headers-3.9.0 vs Guardfile in secure_headers-4.0.0.alpha01

@@ -1,4 +1,5 @@
+# frozen_string_literal: true
 guard :rspec, cmd: "bundle exec rspec", all_on_start: true, all_after_pass: true do
   require "guard/rspec/dsl"
   dsl = Guard::RSpec::Dsl.new(self)
 
   # RSpec files