Add frozen string literal comment to files.

Add frozen string literal comment to files.

diff --git a/jobs/scheduled/check_policy.rb b/jobs/scheduled/check_policy.rb
index 93a5751..94838e0 100644
--- a/jobs/scheduled/check_policy.rb
+++ b/jobs/scheduled/check_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jobs
 
   class ::DiscoursePolicy::CheckPolicy < Jobs::Scheduled
diff --git a/plugin.rb b/plugin.rb
index 611bda1..aba5a80 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # name: discourse-policy
 # about: apply policies to Discourse topics
 # version: 0.1
diff --git a/spec/lib/check_policy_spec.rb b/spec/lib/check_policy_spec.rb
index 248ff8d..b64d711 100644
--- a/spec/lib/check_policy_spec.rb
+++ b/spec/lib/check_policy_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 describe DiscoursePolicy::CheckPolicy do
diff --git a/spec/lib/pretty_text_spec.rb b/spec/lib/pretty_text_spec.rb
index 8776a00..0eb0109 100644
--- a/spec/lib/pretty_text_spec.rb
+++ b/spec/lib/pretty_text_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 describe 'markdown' do
diff --git a/spec/requests/policy_controller_spec.rb b/spec/requests/policy_controller_spec.rb
index 0233999..ba2ccf8 100644
--- a/spec/requests/policy_controller_spec.rb
+++ b/spec/requests/policy_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rails_helper"
 
 describe DiscoursePolicy::PolicyController do
diff --git a/spec/serializers/post_serializer_spec.rb b/spec/serializers/post_serializer_spec.rb
index 386362a..358b613 100644
--- a/spec/serializers/post_serializer_spec.rb
+++ b/spec/serializers/post_serializer_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 describe 'post serializer' do

GitHub sha: 6ddd8afa