get those integers crated and used

test/parfait/test_space.rb

@@ -22,6 +22,17 @@ class TestSpace < MiniTest::Test
     assert @space.false_object , "No lies"
     assert @space.nil_object , "No nothing"
   end
+  def test_integer_first
+    assert @space.next_integer
+  end
+  def test_integer_20
+    int = @space.next_integer
+    20.times do
+      assert int
+      assert_equal Parfait::Integer , int.class
+      int = int.next_integer
+    end
+  end
   def test_methods_booted
     word = @space.get_class_by_name(:Word).instance_type
     assert_equal 4 , word.method_names.get_length