Cookies && Token compatibility

- Fix the root problem with gutenberg infinite loops and allow the token validation/generation if the WP cookie exists.
- More info (Tmeister#138)
- Props: https://github.com/andrzejpiotrowski

Add Changelog Info

Version 1.2.4

* Update firebase/php-jwt to v5.0.0 ( https://github.com/firebase/php-jwt )
* Add Requires PHP Tag

Fix Max recursion error in WordPress 4.7

Solve Tmeister#44

Final Tag 1.2.2 same as WP Repo

Version tested up and stable tag