49 update historical data

[bucketteOfIvy]

Removed an API key found lurking in one of the code files, and transformed the 2010 shapefiles to more closely align with their 2018 equivalents. Specifically:

• Dropped duplicate columns (e.g. tracts2010 had two columns [STATE and STATEFP] containing the same data)
• Renamed and reorganized attribute data to align with the OEPS Geography file metadata and 2018 shapefile attribute data (e.g. TRACT to TRACTCE, and GEO_ID to AFFGEOID).
• Added a GEOID column based on the AFFGEOID column.
• Added state abbreviations to the state file, pulled from the 2018 file.
• Changed LSAD column for states2010 from NA to "00", which is the LSAD designation for states.

The relevant R script is also included.

[bucketteOfIvy]

Woops, this was not an attempt to merge into main

[bucketteOfIvy]

Looked over my code and this feels ready to commit!

[mradamcox]

Looks good @bucketteOfIvy, Next is to finally merge the historical data branch into main.