Version 1.7.1: Quick patch

This version provides a quick patch for a (correct) warning from GCC 8 for the windows options code.

* Fix for Windows style option parsing [#201]
* Improve `add_subcommand` when throwing an exception [#204]
* Better metadata for Conan package [#202]

[#201]: https://github.com/CLIUtils/CLI11/pull/201
[#202]: https://github.com/CLIUtils/CLI11/pull/202
[#204]: https://github.com/CLIUtils/CLI11/pull/204
This tag has no release notes.