Problem with python lib requests and cryptography dependence

[hel-o]

If you install the latest versions:
pip install requests
pip install signxml

the requests lib will broken:

import requests
r = requests.get('https://google.com')

On Ubuntu:

raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='google.com', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLError("bad handshake: Error([('SSL routines', 'ssl3_get_server_certificate', 'certificate verify failed')],)",),))

On Arch the same thing:

raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='google.com', port=443): Max retries exceeded with url: / (Caused by SSLErr
or(SSLError("bad handshake: Error([('SSL routines', 'tls_process_server_certificate', 'certificate verify failed')],)",),))

After reviewing the dependencies, this issue can be fixed upgrading the signxml dependence cryptography to new version:
cryptography==2.1.4 or 'cryptography >= 1.8, < 2.2',