flutter_data_json_api_adapter support for 2.0.0

[domtom1126]

Hey Frank, is there a plan to update flutter_data_json_api_adapter so it's compatible with 2.0.0?

[domtom1126]

@frank06 Here is a PR for a flutter_data_json_api_adapter to make it compatible with FD 2.0.0

Flutter Data upgrade PR

[frank06]

flutterdata/flutter_data_json_api_adapter#4