Fix AJ tests on ruby 2.4 being causes since classes are unified for Integer, and we create test name nased on arg class. Append ar as well to the test name

activejob/test/cases/argument_serialization_test.rb

@@ -14,7 +14,7 @@ class ArgumentSerializationTest < ActiveSupport::TestCase
     [ 1, 'a' ],
     { 'a' => 1 }
   ].each do |arg|
-    test "serializes #{arg.class} verbatim" do
+    test "serializes #{arg.class} - #{arg} verbatim" do
       assert_arguments_unchanged arg
     end
   end