Rakefile in keep_up-0.6.3 vs Rakefile in keep_up-0.7.0

@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
 require 'cucumber/rake/task'
 
 RSpec::Core::RakeTask.new(:spec)