Rubocop updates & binstubs

Rakefile

@@ -1,6 +1,12 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
 
 RSpec::Core::RakeTask.new(:spec)
 
-task :default => :spec
+require "rubocop/rake_task"
+
+RuboCop::RakeTask.new
+
+task default: %i[rubocop spec]