use of fast core types prevents basic operations like json.dumps on a response

[kapilt]

afaics the use of fast core types like L prevents basic operations like serializing the response from ghapi.

 >>> json.dumps(o)
*** TypeError: Object of type L is not JSON serializable

[hugovk]

There's a workaround at #66 (comment) using from fastcore.xtras import obj2dict.