update process.py and execute to update data

[bgrayburn]

updated the processing script to unpack the zipfile version of the worldbank data. had to modify a few values to fit the file format such as to accommodate skipping more initial rows. once it was working I updated the data/gdp.csv to the latest data (which appears to have the most recent values from 2021).

[michal-josef-spacek]

I think you need to update .github directory too. There is e.g. .github/datapackage.json with "last_updated": "2018-01-19",