Create race and ethnicity categorization scripts to match FFIEC

[Kibrael]

For 2018:
https://github.com/cfpb/hmda-platform/wiki/Race-Categorization-2018-(v2)
https://github.com/cfpb/hmda-platform/wiki/Ethnicity-Categorization---V2-2018

For 2017 and prior:
Use historic FFIEC logic

Using FFIEC logic maintains comparability of data over time with official reports generated by the FFIEC.