cqi.parse_qs deprecated

[gilleslandais]

Hello -
thank you for your library - very useful !

I report an issue that I discover recently after an ubuntu migration from bionic to focal which migrates python3.6 to python3.8.
I installed pyoai, but there is a problem with oaipmh/server.py that uses cgi.parse_qs:

AttributeError: module 'cgi' has no attribute 'parse_qs'

It seems that the method is deprecated - see eventlet/eventlet#580

Thank for your development,
Gilles Landais