Guardfile in hackerone-client-0.15.0 vs Guardfile in hackerone-client-0.16.0

@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 guard :rspec, cmd: "bundle exec rspec" do
   require "guard/rspec/dsl"
   dsl = Guard::RSpec::Dsl.new(self)
 
   # Feel free to open issues for suggestions and improvements