Raven proxy usage

[vierja]

I'm trying to integrate Sentry with some apps that are deployed in an environment that doesn't allow non-proxied requests to the outside world. I can't use the HTTP(S)_PROXY environment variables because I still need to make requests without any proxy.

Any suggestions? I am willing to dive into the code and make a PR if necessary. Any pointers are helpful.

[ghost]

@vierja use requests transport https://github.com/getsentry/raven-python/blob/master/raven/transport/requests.py you can modify it to support proxy http://docs.python-requests.org/en/master/user/advanced/#proxies

it will be good if raven adds this feature into itself