Aggregate sir-complains-a-lot complaints by source

[benjaminysmith]

Currently we get too many individual complaints:

usa-facts confirmed_7dav_cumulative_prop (county, hrr, msa, state) has a 2-day gap of missing data in its most recent 7 days of data; last updated 2020-11-05.
usa-facts confirmed_7dav_incidence_num (county, hrr, msa, state) has a 2-day gap of missing data in its most recent 7 days of data; last updated 2020-11-05.
...

We can pull these together into a single line for the source:

usa-facts has a 2-day gap of missing data for N signals (confirmed_7dav_cumulative_prop, confirmed_7dav_incidence_num, etc.)