Add users factory for tests

config/environments/test.rb

@@ -6,6 +6,9 @@
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
   
+  # For Devise
+  config.action_mailer.default_url_options = { host: 'localhost:3000' }
+
   config.cache_classes = false
 
   # Do not eager load code on boot. This avoids loading your whole application