`TwitchObject` is not natively JSON serializable

[Nathan Klapstein]

Due to using a datetime.datetime instance in TwitchObject, TwitchObject is not natively JSON serializable.

Example:

json.dumps(client.search.channels("example"))

Running this will result in:

Traceback (most recent call last):
  File ".../twitch-viewer/proto.py", line 17, in <module>
    print(json.dumps(client.search.channels("example")))
  File "/usr/lib/python3.6/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python3.6/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.6/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python3.6/json/encoder.py", line 180, in default
    o.__class__.__name__)
TypeError: Object of type 'datetime' is not JSON serializable

Though this can be addressed on the developers end. I feel that a TwitchObject should be able to be easily converted into JSON without additional effort.

A easy solution would be to use a str or int timestamp (eg: from epoc) for dates in a TwitchObject instead of using a datetime.datetime instance.