Update how we check verify when inspecting env variables
Replace dead link with StackOverflow answer
Merge pull request #2116 from sigmavirus24/fix-2107

Replace dead link with StackOverflow answer
Fix silly check
Merge pull request #2115 from sigmavirus24/fix-2092

Update how we check verify when inspecting env variables
Preferentially use certifi to requests.
Install certifi with requests.
Merge pull request #2124 from Lukasa/certifi

Depend on certifi
Fix broken link
Merge pull request #2128 from tshepang/patch-1

Fix broken link
Apply environment features to prepared requests

By having trust environment lookup in request() applications using
prepared requests don't get access to this functionality. Having this in
send() is a more logical place as we are dealing with default
communication parameters.

Closes #1436