Unavailable certificate when reading prebid bidder-data.csv

[dshore]

Description

Some users may get the following when code tries to access the bidder-data.csv file:

urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:997)>

Fix

Specify trusted CA certificates:

import certifi
import ssl
from urllib import request

context = ssl.create_default_context(cafile=certifi.where())

_x = [l.decode('utf-8') for l in \
      request.urlopen('https://docs.prebid.org/dev-docs/bidder-data.csv',
                      context=context).readlines()]