added rubocop to development dependency

hsbt · hsbt · commit aedc33ca9c17 · 2017-08-21T11:42:13.000+09:00
diff --git a/rake.gemspec b/rake.gemspec
@@ -39,4 +39,5 @@ Rake has the following features:
   s.add_development_dependency(%q<minitest>.freeze)
   s.add_development_dependency(%q<rdoc>.freeze)
   s.add_development_dependency(%q<coveralls>.freeze)
+  s.add_development_dependency(%q<rubocop>.freeze)
 end
