Apply aggregate to the Coordinates class

[wu-geoff]

Turning the latitude and longitude into protected variables, because there is no point making them public.

PS: It passed all the unit tests.

[Kilo59]

I don't think this adds much value.
If you are just looking to get some open source commits under your built you could convert this model into a pydantic model and add some tests to verify the model passes/fails validation when appropriate values are passed.

I would approve and merge that.

[wu-geoff]

I converted the Coordinates class to a pydantic model, and I specified the two fields (latitude and longitude) to be floats. Since NYT doesn't provide coordinates, the two fields can be set to None.
There are a couple things I must point out though:

1. By specify the latitude and longitude to be float, they're no longer returned as strings in the responses. Instead, they're returned as floats, which might break backward compatibility.
2. Also, since latitude and longitude are floats, if for some reasons the two fields are missing or just empty strings in the original data sets (e.g. in the JHU data set, the latitude and longitude of the Canadian Repatriated Travellers are both empty strings, for unknown reasons), they're now nulls in the JSON response, which, again, might break backward compatibility.

Let me know if you have any thoughts or opinions regarding my PR.