Rakefile in sentry-rails-5.20.1 vs Rakefile in sentry-rails-5.21.0

@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
 
 RSpec::Core::RakeTask.new(:spec).tap do |task|
   task.rspec_opts = "--order rand"