Log Message:
py-urllib3: updated to 1.25

1.25:
* Require and validate certificates by default when using HTTPS.
* Upgraded urllib3.utils.parse_url() to be RFC 3986 compliant.
* Added support for key_password for HTTPSConnectionPool to use
  encrypted key_file without creating your own SSLContext object.
* Add TLSv1.3 support to CPython, pyOpenSSL, and SecureTransport SSLContext
  implementations.
* Switched the default multipart header encoder from RFC 2231 to HTML 5 working \ 
draft.
* Fixed issue where OpenSSL would block if an encrypted client private key was
  given and no password was given. Instead an SSLError is raised.
* Added support for Brotli content encoding. It is enabled automatically if
  brotlipy package is installed which can be requested with
  urllib3[brotli] extra.
* Drop ciphers using DSS key exchange from default TLS cipher suites.
  Improve default ciphers when using SecureTransport.
* Implemented a more efficient HTTPResponse.__iter__() method.