Don't mask TwythonStreamer exceptions

Exceptions in handlers or on_success which subclass ValueError would
previously be caught and reported as a JSON decoding problem, and
on_error() would be called (with status_code=200).
Update setup.py

Copied setup import from Python-Requests so it does not fail on some platforms (e.g. Nokia N9/MeeGo).
Merge pull request #275 from Hasimir/patch-1

Update setup.py
Merge pull request #271 from remram44/dont-catch-streamer-errors

Don't mask TwythonStreamer exceptions
Merge remote-tracking branch 'main/master'