only call methods that are on the superclass

We want to treat the response object as if it's a real response object
(not a test object), so we should only call methods that are on the
superclass.

actionpack/test/controller/action_pack_assertions_test.rb

@@ -318,7 +318,7 @@ def test_server_error_response_code
 
   def test_missing_response_code
     process :response404
-    assert @response.missing?
+    assert @response.not_found?
   end
 
   def test_client_error_response_code
@@ -346,7 +346,7 @@ def test_redirection
 
   def test_successful_response_code
     process :nothing
-    assert @response.success?
+    assert @response.successful?
   end
 
   def test_response_object

actionpack/test/controller/filters_test.rb

@@ -819,7 +819,7 @@ def test_a_rescuing_around_action
       response = test_process(RescuedController)
     end
 
-    assert response.success?
+    assert response.successful?
     assert_equal("I rescued this: #<FilterTest::ErrorToRescue: Something made the bad noise.>", response.body)
   end
 

actionpack/test/dispatch/test_response_test.rb

@@ -11,10 +11,9 @@ def assert_response_code_range(range, predicate)
   end
 
   test "helpers" do
-    assert_response_code_range 200..299, :success?
-    assert_response_code_range [404],    :missing?
-    assert_response_code_range 300..399, :redirect?
-    assert_response_code_range 500..599, :error?
+    assert_response_code_range 200..299, :successful?
+    assert_response_code_range [404],    :not_found?
+    assert_response_code_range 300..399, :redirection?
     assert_response_code_range 500..599, :server_error?
     assert_response_code_range 400..499, :client_error?
   end