Missing include parameter

[dikastes]

Until now, the include parameter of the API, which serves for including special data formats, may not be used.

I will open a PR which would add this feature, if you're interested.

[hedii]

Hello,

I am not using this package anymore, but please submit a pull request.

Please be careful about php and guzzle version constrain (I saw your previous PR which included return types and a new guzzle version, i think it should not).