Set config.cache_classes to false as required by Github CI

config/environments/test.rb

@@ -9,6 +9,7 @@
   # Settings specified here will take precedence over those in config/application.rb.
 
   # While tests run files are not watched, reloading is not necessary.
+  config.cache_classes = false
   config.enable_reloading = false
   config.action_view.cache_template_loading = true