Build minichlink in CI (#148)

* Fix caching

* Create requirements.txt

* Fix PlatformIO build for Wiring examples, use cache properly

* Remove uneeded file

* Add slightly more into PlatformIO ini

* Build minichlink in CI (linux)

* Build minichlink in CI (linux)

* Build minichlink in CI (linux), try 3

* Build minichlink in CI (Windows

* Build minichlink in CI (clean)

* Build minichlink in CI (clean 2)

* Build minichlink in CI (MacOs12)

* Build minichlink in CI (MacOs12)

* Fix archive creation

* Fix archive creation 2

* Build for MacOS 11 too