Port to Python 3
Tahoe-LAFS 1.17.0 now supports Python 3 which means the path is largely clear for ZKAPAuthorizer to support Python 3. Python 2 is long since EOL. This needs to happen.
Tahoe-LAFS 1.17.0 now supports Python 3 which means the path is largely clear for ZKAPAuthorizer to support Python 3. Python 2 is long since EOL. This needs to happen.