Fixed MockPersistence to handle rename correctly

test/helpers.rb

@@ -1,21 +1,24 @@
 class MockPersistence
+  attr_reader :entities
   def initialize
-    @objects = {}
+    @entities = {}
   end
   def find_entity(name)
-    @objects[name]
+    @entities[name]
   end
   def add_entity(entity)
-    @objects[entity.name] = entity
+    @entities[entity.name] = entity
     entity
   end
   def delete_entity(name)
-    @objects.delete(name)
+    @entities.delete(name)
   end
   def save_entity(entity)
-    @objects[entity.name] = entity
-  end
-  def entities
-    @objects
+    if(@entities[entity.name])
+      @entities[entity.name] = entity
+    else
+      @entities.delete_if { |name, ent| ent.name == entity.name }
+      add_entity(entity)
+    end
   end
 end

test/test_session.rb

@@ -811,8 +811,6 @@ def test_rename
       entity = @session.create_entity(entity_name, 'entity_pass')
       @session.rename(entity_name, new_name)
       refute_nil(@session.find_entity(new_name))
-      assert_equal(new_name, @session.find_entity(entity_name).name)
-      skip("Niklaus is unsure whether only MockPersistence is wrong or if this an error in the yus implementation")
       assert_nil(@session.find_entity(entity_name))
     end
   end