Add U.S. territories to state2abbr() and abbr2state() #7
Description
If possible, it would be great if state2abbr() and abbr2state() included U.S. territories, i.e. those listed on this page (https://www.census.gov/library/reference/code-lists/ansi/ansi-codes-for-states.html) under "FIPS Codes for Outlying Areas of the United States and the Freely Associated States"