Support setting examples for response

Add helper method `response_examples` to inject response examples to swagger

rswag-specs/lib/rswag/specs/example_group_helpers.rb

@@ -25,7 +25,7 @@ module Rswag
       # functionality while also setting the appropriate metadata if applicable
       def description(value=nil)
         return super() if value.nil?
-        metadata[:operation][:description] = value 
+        metadata[:operation][:description] = value
       end
 
       # These are array properties - note the splat operator
@@ -61,6 +61,10 @@ module Rswag
         metadata[:response][:headers][name] = attributes
       end
 
+      def response_examples(example)
+        metadata[:response][:examples] = example
+      end
+
       def run_test!
         # NOTE: rspec 2.x support
         if RSPEC_VERSION < 3