security/py-{acme,certbot}: update to 0.15.0

Common:

• Update PORTVERSION and distinfo checksum (0.15.0)
• Update RUN/TEST dependencies
• Remove unnecessary patches (applied upstream)

Changes: https://github.com/certbot/certbot/blob/master/CHANGELOG.md#0150---2017-06-08

Reviewed by: koobs
Approved by: koobs (maintainer, py-certbot)
Differential Revision: https://reviews.freebsd.org/D10612