JSON parse error in "confirmed" endpoint

[balsama]

Hi. Thanks for putting this together.

The response from https://covid19api.herokuapp.com/confirmed is returning invalid json currently. Specifically:

Error: Parse error on line 15322:
...": 0,			"3/23/20": NaN,			"3/3/20": 0,
----------------------^
Expecting 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '[', got 'undefined'

[stopyransky]

yeah i think issue is related to the source CSSEGISandData/COVID-19#1372
seems that they tried to add granulation to US data but messed the whole dataset.
IT seems that now timeseries files are depreciated and will not be updated - they use different files:
info here: CSSEGISandData/COVID-19#1355

[Omaroid]

I've corrected the files to support the new changes in the dataset. Check the readme for more details.