Describe the bug
When I use closure for format as written in documentation,
an error Warning: date() expects parameter 1 to be string, object given occurs.

To Reproduce

// Warning: date() expects parameter 1 to be string, object given
new Timestampable([
            'beforeCreate' => [
                'field

Hey,

I did a lot of work for authorization for your project. The first one is to use your project with concrete5 and the second one is to authorize the requests with jwt including the websocket server. This would maybe be a good example package for your documentation, how somebody could include authorization? I know it's not an issue, but i dont know how to reach you :)
https://github.com/lemo

As of #29 mentioned, the usage of flex entity will break some static analyzer. It might be a good idea to add hoa\devtools to suggest package.