Consider adding vintage NCHS mortality data from the CDC

[krivard]

Roni forwarded Alex and I an archive file for https://www.cdc.gov/nchs/nvss/vsrr/COVID19/index.htm.

Roni says:

official Covid-related mortality data (alas, state-level only and with ~2 week backfill)

Not urgent, but may prove useful to modeling/forecasting.

[krivard]

Archive file has been dropped on midas at: /common/krivard/VSRR_COVID19_Counts_April-June26.tgz

[krivard]

Katie will check with Roni about:

• Can we get more historical data between Feb and April?
• Can we get better file formats for April-May?
• Can we get historical data between June 26 and July 20?

[krivard]

Roni advised going directly to Matthew with detailed questions; sent on 21 July and no response.

We should see about moving forward with this using the (easier) current format, and backfilling this archive file once we can resolve the questions we have about it.

[krivard]

Fairly straightforward, expect to complete this week.

[krivard]

Blocked on #158; needs extended signal name support.

[krivard]

Adding a signal for "deaths in excess of expected deaths" as a percent of the average deaths for previous years.

Additionally we'll want to adapt the issue builder utility to handle weekly datasets. @dshemetov to consult as needed.

[jingjtang]

New PR here