Use `io` module instead of `codecs`
Use `io` module instead of `codecs`

See https://mail.python.org/pipermail/python-list/2015-March/687124.html

stweil/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,stweil/letsencrypt