Update to rails 4.2.3

config/initializers/action_dispatch.rb

@@ -1,2 +1,17 @@
 # Stop rails from automatically parsing XML in request bodies
 Rails.configuration.middleware.delete ActionDispatch::ParamsParser
+
+# https://github.com/rails/rails/issues/20710
+module ActionDispatch
+  module Assertions
+    def html_document_with_rss
+      @html_document ||= if @response.content_type == Mime::RSS
+                           Nokogiri::XML::Document.parse(@response.body)
+                         else
+                           html_document_without_rss
+                         end
+    end
+
+    alias_method_chain :html_document, :rss
+  end
+end