SSL: CERTIFICATE_VERIFY_FAILED errors during local pipeline run.

[tneymanov]

When running the tool locally, the following error pops up.

Traceback (most recent call last):
  File "gcp_variant_transforms/testing/integration/run_vcf_to_bq_tests.py", line 317, in 
    ret_code = main()
  File "gcp_variant_transforms/testing/integration/run_vcf_to_bq_tests.py", line 301, in main
    with TestContextManager(args) as context:
  File "gcp_variant_transforms/testing/integration/run_vcf_to_bq_tests.py", line 204, in __enter__
    _ = client.create_dataset(dataset)  # See #171, pylint: disable=no-member
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/cloud/bigquery/client.py", line 348, in create_dataset
    api_response = self._call_api(retry, method="POST", path=path, data=data)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/cloud/bigquery/client.py", line 400, in _call_api
    return call()
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/api_core/retry.py", line 270, in retry_wrapped_func
    on_error=on_error,
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/api_core/retry.py", line 179, in retry_target
    return target()
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/cloud/_http.py", line 299, in api_request
    headers=headers, target_object=_target_object)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/cloud/_http.py", line 193, in _make_request
    return self._do_request(method, url, headers, data, target_object)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/cloud/_http.py", line 223, in _do_request
    body=data)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google_auth_httplib2.py", line 187, in request
    self._request, method, uri, request_headers)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/auth/credentials.py", line 122, in before_request
    self.refresh(request)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/oauth2/service_account.py", line 322, in refresh
    request, self._token_uri, assertion)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/oauth2/_client.py", line 145, in jwt_grant
    response_data = _token_endpoint_request(request, token_uri, body)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google/oauth2/_client.py", line 106, in _token_endpoint_request
    method='POST', url=token_uri, headers=headers, body=body)
  File "/tmp/tmp.ZfVM9FCvpG/local/lib/python2.7/site-packages/google_auth_httplib2.py", line 119, in __call__ 
    raise exceptions.TransportError(exc)
google.auth.exceptions.TransportError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:661)

The issue is caused by the outdated httplib2 package due to a dependency enforced by <=2.4 versions of Apache Beam (upgrade of apache beam is also blocked and is discussed here. As a workaround users can manually update httplib2 on their system via following command:

pip install --upgrade --user httplib2

So far, no issues caused by this manual upgrade have been observed.