Revert "Add a migration to allow the use of the fuzzystrmatch extension"

This reverts commit ba5847c967a9e8354c39da6d633f454607051b9a.
Back out the code for using Levenshtein distance for fuzzy name matching
Add 'requests' to requirements.txt
Add some safe guesses for the last few names
Don't delete currently incorrect aspirant information

(There was actually an error in this code anyway.)  Instead of
deleting these positions, set an end_date for them which represents
the data import data.
Remove the warning about missing aspirant data
Merge branch 'master' into production