Encoding for GPG

[Tim Heithecker]

python-gnupg >= 0.3.6 uses "latin-1" as default encoding.
That makes email_extras.utils.send_mail('Subject', '(U+015B): ś', ... fail.

Possible fix: master...theithec:master

[stephenmcd]

I merged your fix and pushed a new version to PyPI.

Thanks!