Gemfile in red_amber-0.1.5 vs Gemfile in red_amber-0.1.6

@@ -10,9 +10,10 @@
   gem 'rubocop'
   gem 'rubocop-performance', require: false
   gem 'rubocop-rake'
   gem 'rubocop-rubycw', require: false
 
+  gem 'iruby'
   gem 'test-unit'
   gem 'webrick'
 
   gem 'benchmark_driver'
   gem 'red-datasets-arrow'