Use ActiveModel::TestCase instead of Test::Unit:TestCase

Author: rafaelfranca

activemodel/test/cases/naming_test.rb

@@ -210,7 +210,7 @@ def test_i18n_key
   end
 end
 
-class NamingHelpersTest < Test::Unit::TestCase
+class NamingHelpersTest < ActiveModel::TestCase
   def setup
     @klass  = Contact
     @record = @klass.new
@@ -276,7 +276,7 @@ def method_missing(method, *args)
     end
 end
 
-class NameWithAnonymousClassTest < Test::Unit::TestCase
+class NameWithAnonymousClassTest < ActiveModel::TestCase
   def test_anonymous_class_without_name_argument
     assert_raises(ArgumentError) do
       ActiveModel::Name.new(Class.new)