Gemfile in d_heap-0.2.1 vs Gemfile in d_heap-0.2.2

@@ -1,8 +1,11 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 # Specify your gem's dependencies in d_heap.gemspec
 gemspec
 
 gem "rake", "~> 13.0"
 gem "rake-compiler"
 gem "rspec", "~> 3.10"
+gem "rubocop", "~> 1.0"