Proxy settings in session instances not honored.

[palbee]

When creating a client with a request.Sessions instance the proxies field is ignored. While proxies may be configured via environment variables, they should also be configurable via session objects.

[lovelydinosaur]

Can you give me an example of what we'd need to change to support this?

[lovelydinosaur]

Okay, this should be fixed in master, and the upcoming 3.0 release. (We use session.request now, rather than building the request then sending it. The environment will get set properly for us.)