fixed:  test: Tree should delete child. (TestMongoidActsAsTree): NoMethodError: undefined method 'parent_id_field' for BSON::ObjectID
fixed:  test: Tree should delete child. (TestMongoidActsAsTree):
NoMethodError: undefined method 'parent_id_field' for BSON::ObjectID

saks/mongoid_acts_as_tree,astevens/mongoid_acts_as_tree