pass the auth_token to linked objects

so that you can still link off of the returned object.

Before this change, if you tried to link more then 1 level deep from a base object, it would throw an error because your linked object does not have an auth token.

To reproduce:

```
district = CleverDistrict.find.first # includes district["auth_token"]
school = district.schools.first # does NOT include school["auth_token"]
school.sections
```

This will throw an authentication error because the school will not have the auth_token param.