Sslkeylog

-------------------
Fixed
^^^^^
* Fix build issue due to wrong type of ``sslkeylog_ex_data_dup``
(`16 <https://github.com/segevfiner/sslkeylog/pull/16>`_).

-------------------
Added
^^^^^
* Windows support for Python builds with OpenSSL 3.0

Removed
^^^^^^^
* CI for Python 2.7 & 3.6 as support was removed from GitHub Actions. Though the package itself
should still work with those versions.

-------------------

Added
^^^^^
* CI using GitHub Actions. Sadly can't test on Windows Python 2.7 anymore since Microsoft just nuked
the compilers for it from existence some time ago.
* Added `get_server_random` and `export_keying_material`.
* Add a guard to prevent using sslkeylog with a different version of OpenSSL at runtime then build time.

-------------------

Changed
^^^^^^^
* ``set_keylog(None)`` will no longer trigger monkey patching, making it easier to use it
conditionally.
* Updated documentation to show how to support ``SSLKEYLOGFILE``.
* Document that some methods don't work with TLS v1.3 as the values they are meant to return
don't exist anymore in TLS v1.3.

Fixed
^^^^^
* Fix tests when TLS v1.3 is enabled by default.

-------------------

Added
^^^^^
* Support for OpenSSL 1.1.1 and TLS 1.3
* Support setting keylog to ``None`` to disable.

Fixed
^^^^^
* Fix tests on Linux.

-------------------
Fix a broken URL in README.rst.