Revise data model

[elaguerta]

1. Consider including active/recovered cases. Solano County and Sonoma county have these.
2. Research and implement best practices for demographic categories. In particular, we might prefer:

• Black, replaces African_Amer
• American_Indian_Alaska_Native, replaces Native_Amer
• Latinx, replaces Latinx_or_Hispanic

[elaguerta]

@ldtcooper When the data viz team comes back with an answer on age groups, we might include that in this issue.

[elaguerta]

Goals to address in this issue:

• Update current scrapers to report race/eth categories per counties
• Update current scrapers to report age categories per counties, and format per:
  old:

 "age_group": [  
  {"group": "0_17_yrs", "raw_count": 10},  
  {"group": "18_49_yrs", "raw_count": 10},
  ...

new:

"age_group": [
  {"group": "0-17", "raw_count": 10},
  {"group": "18-49", "raw_count": 10},
  ...
]

• Update data_model.json to reflect above changes to race/eth and age categories

• Update README to communicate above changes