sxross/MotionModel — pull request #4 by dr-skot (2012-10-10 04:37:36+00:00)
Title: fixed deserialize and serialize without filename argument

`deserialize_from_file` and `serialize_to_file` were not working as advertised when the `file_name` argument was omitted. The fix was to change

```ruby
@file_name ||= file_name
```
to
```ruby
@file_name = file_name if file_name
```
and to be sure and use `@file_name` not `file_name` thereafter.

Also added some tests in `persistence_spec.rb`

Thanks for this handy module!