Add configurable timeout to ET requests.

@jgmize I think this will help too. Should keep basket from churning forever.
I'd still like to check into catching this particular timeout and catching it
with statsd or something.
While this looks good in theory, I can't find where setting the timeout here actually does something in https://github.com/mozilla/basket-lib/blob/master/packages/suds/suds/client.py other than just storing the key value pair in the Client.options dict. What am I missing?