Retry on any ConnectionError exception
Retry on any ConnectionError exception

- Fixes #47 / SC-404

Signed-off-by: lsenta <93e2db26c7714cc3fb230d05f2fbedc450bb1db9@gmail.com>

torymur/python-hubstorage,scrapinghub/python-hubstorage,kalessin/python-hubstorage