use io.open and update classifiers
use io.open and update classifiers

Signed-off-by: Chris Warrick <de6f931166e131a07f31c96c765aee08f061d1a5@gmail.com>

mfussenegger/pkgbuilder,mfussenegger/pkgbuilder,Kwpolska/pkgbuilder,Kwpolska/pkgbuilder