Support county-level data

[patricksheehan]

We want to support county-level data, this will involve:

• Connecting to a county-level data source
• Transforming county-level data (as-necessary)
• Storing county-level data for use in the website / hero map
• Adding county-level tables and visualizations to the website

I think the order of operations should be:
(1) Identify what county-level data exists
(2) Given that information, design the components we will add to the website
(3) Setup a "dummy" data set to integrate website changes against
(4a) Connect, transform, and store real data (backend task)
(4b) Add website features to incorporate county data (frontend task)

[patricksheehan]

@lucasmbrown @rypan @devinhunt my thought is this can be the primary issue for the county-level data "epic".

(1) Does this organization make sense (a main issue, and we can create sub issues that reference it)?
(2) Have I captured all the steps required?
(3) Does the order of operations make sense?

I'll take the data sources we've identified and report back what data fields are available so we can get going on design.