japanese_calendar.gemspec in japanese_calendar-0.3.1 vs japanese_calendar.gemspec in japanese_calendar-0.3.2

@@ -19,11 +19,14 @@
   end
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.required_ruby_version = ">= 2.1"
+
   spec.add_development_dependency "bundler", "~> 1.13"
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec", "~> 3.0"
+  spec.add_development_dependency "rubocop"
   spec.add_development_dependency "simplecov"
   spec.add_development_dependency "codeclimate-test-reporter", "~> 1.0.0"
 end