Drop monkey patches that are no longer required

config/initializers/action_dispatch.rb

@@ -1,17 +1,2 @@
 # 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

config/initializers/omniauth.rb

@@ -38,16 +38,3 @@ Rails.application.config.middleware.use OmniAuth::Builder do
   provider :github, GITHUB_AUTH_ID, GITHUB_AUTH_SECRET, github_options if defined?(GITHUB_AUTH_ID)
   provider :mediawiki, WIKIPEDIA_AUTH_ID, WIKIPEDIA_AUTH_SECRET, wikipedia_options if defined?(WIKIPEDIA_AUTH_ID)
 end
-
-# Pending fix for: https://github.com/intridea/omniauth/pull/795
-module OmniAuth
-  module Strategy
-    def mock_callback_call_with_origin
-      @env["omniauth.origin"] = session["omniauth.origin"]
-
-      mock_callback_call_without_origin
-    end
-
-    alias_method_chain :mock_callback_call, :origin
-  end
-end