show version on route

Author: Jerry Cheung

lib/grape/route.rb

@@ -16,7 +16,7 @@ def method_missing(method_id, *arguments)
     end
 
     def to_s
-      "#{route_method} #{route_path}"
+      "Version: #{route_version} #{route_method} #{route_path}"
     end
 
   end