Create the persistence layer

> I think we can maintain the Interface type hiting.

The [previous][1] [interface][2] does not have [the methods][3] we use.

[2]: https://github.com/zendframework/zf2/blob/master/library/Zend/Stdlib/MessageInterface.php
[1]: https://github.com/zendframework/zf2/blob/master/library/Zend/Stdlib/RequestInterface.php
[3]: https://github.com/zendframework/zf2/blob/master/library/Zend/Http/Request.php#L330