rack_check.gemspec in rack_check-0.2.0 vs rack_check.gemspec in rack_check-0.2.2

@@ -23,6 +23,7 @@
   spec.add_development_dependency "bundler", "~> 1.11"
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_runtime_dependency "rspec", "~> 3.0"
   spec.add_runtime_dependency "concurrent-ruby", "~> 1.0"
   spec.add_runtime_dependency "http", "~> 2.2"
+  spec.add_runtime_dependency "open4", "~> 1.3"
 end