discover webmention endpoints in the Link HTTP response header

also don't verify SSL certs. python-requests's verification is overly aggressive.

fixes #7. thanks again for the find, @jeena!
Merge branch 'master' of https://github.com/snarfed/webmention-tools

Discover webmention endpoints in the Link HTTP response header
also don't verify SSL certs. python-requests's verification is overly
aggressive.
Fixes #7. thanks again for the find, @jeena!