remove the last_object from chain

also tried to keep the first around as was done in space
partially to not have to add the consrtants seperately
didn't work, as chain gets broken
also this has to be redone anyway

test/parfait/test_factory.rb

@@ -1,7 +1,7 @@
 require_relative "helper"
 
 module Parfait
-  class TestPage < ParfaitTest
+  class TestFactory < ParfaitTest
 
     def setup
       super
@@ -18,12 +18,15 @@ module Parfait
     end
     def test_no_next
       assert_nil @factory.next_object
-      assert_nil @factory.last_object
       assert_nil @factory.reserve
     end
     def test_get_next_object
       assert_equal Parfait::Integer ,  @factory.get_next_object.class
     end
+    def test_first_is_reserve
+      @factory.get_next_object
+      assert_equal Parfait::Integer , @factory.reserve.class
+    end
     def test_chain_length
       count = 0
       start = @factory.get_next_object