Update US case counts source

[joverlee521]

Our current US case count source was no longer updated as of 10/20/2022.

There is a new CDC data source, but this reports cases by week instead of by day.

[joverlee521]

I did not notice the US case counts was no longer updated because the automated pipeline only notifies when the upload has updated the file on S3. It does not send notifications when the file is identical to the S3 file. This should be changed so that we get alerted if the case counts do not get updated.

[joverlee521]

Alternative sources:

• NYTimes has a public repo for US case counts, but the daily counts are cumulative
• John Hopkins has a public repo for case counts, with US case counts split by county and wide date columns with daily counts that are cumulative

[marlinfiggins]

I'd recommend the NYT's case data. Their us-states.csv seems to be basically exactly what we need other than just taking a diff for cases between consecutive days.