Merge pull request activeadmin#1415 from jpmckinney/use_display_name_in_breadcrumb

Use display_name helper in breadcrumb

Author: pcreux

lib/active_admin/view_helpers/breadcrumb_helper.rb

@@ -14,7 +14,7 @@ def breadcrumb_links(path = nil)
             begin
               parent_class = parent.singularize.camelcase.constantize
               obj = parent_class.find(part.to_i)
-              name = obj.display_name if obj.respond_to?(:display_name)
+              name = display_name(obj)
             rescue
             end
           end