Release/0.6.0

[matus-tomlein]

This release updates the Newtonsoft.Json library which makes it compatible with newer versions of Unity.

Changelog

• Update Newtonsoft.Json.dll to 13.0.1 (#53)
• Update SnowplowTracker.Tests to Unity 2021.3.12f1 (#55)
• Update SnowplowTracker.Demo to Unity 2021.3.12f1 (#54)

Under the hood

• Update versions in Github actions (#57)

SnowplowTracker.unitypackage.zip