1.26.0 (2020-11-10)

* **NOTE: urllib3 v2.0 will drop support for Python 2**.

`Read more in the v2.0 Roadmap <https://urllib3.readthedocs.io/en/latest/v2-roadmap.html>`_.

* Added support for HTTPS proxies contacting HTTPS servers (Pull #1923, Pull #1806)

* Deprecated negotiating TLSv1 and TLSv1.1 by default. Users that

still wish to use TLS earlier than 1.2 without a deprecation warning

should opt-in explicitly by setting ``ssl_version=ssl.PROTOCOL_TLSv1_1`` (Pull #2002)

**Starting in urllib3 v2.0: Connections that receive a ``DeprecationWarning`` will fail**

* Deprecated ``Retry`` options ``Retry.DEFAULT_METHOD_WHITELIST``, ``Retry.DEFAULT_REDIRECT_HEADERS_BLACKLIST``

and ``Retry(method_whitelist=...)`` in favor of ``Retry.DEFAULT_ALLOWED_METHODS``,

``Retry.DEFAULT_REMOVE_HEADERS_ON_REDIRECT``, and ``Retry(allowed_methods=...)``

(Pull #2000) **Starting in urllib3 v2.0: Deprecated options will be removed**

* Added default ``User-Agent`` header to every request (Pull #1750)

* Added ``urllib3.util.SKIP_HEADER`` for skipping ``User-Agent``, ``Accept-Encoding``,

and ``Host`` headers from being automatically emitted with requests (Pull #2018)

* Collapse ``transfer-encoding: chunked`` request data and framing into

the same ``socket.send()`` call (Pull #1906)

* Send ``http/1.1`` ALPN identifier with every TLS handshake by default (Pull #1894)

* Properly terminate SecureTransport connections when CA verification fails (Pull #1977)

* Don't emit an ``SNIMissingWarning`` when passing ``server_hostname=None``

to SecureTransport (Pull #1903)

* Disabled requesting TLSv1.2 session tickets as they weren't being used by urllib3 (Pull #1970)

* Suppress ``BrokenPipeError`` when writing request body after the server

has closed the socket (Pull #1524)

* Wrap ``ssl.SSLError`` that can be raised from reading a socket (e.g. "bad MAC")

into an ``urllib3.exceptions.SSLError`` (Pull #1939)