fixup! test: add unit tests for two-factor model, strategy, and registration

Author: santiagorodriguez96

test/devise_test.rb

@@ -109,13 +109,6 @@ class DeviseTest < ActiveSupport::TestCase
     end
   end
 
-  test 'add_module no longer accepts two_factor option' do
-    assert_raises(ArgumentError) do
-      Devise.add_module(:test_mod, two_factor: true)
-    end
-    Devise::ALL.delete(:test_mod)
-  end
-
   test 'Devise.secure_compare fails when comparing different strings or nil' do
     [nil, ""].each do |empty|
       assert_not Devise.secure_compare(empty, "something")