General:
* Updated to newest MC version (12.2)
* Removed Spigot updater
* Implemented Marketplace updater

Marketplace:
* Moved the project over to Marketplace
* Future updates will not be released anymore on Spigot
* Support will only take place on Marketplace

* Link: http://herbystar.eu/resources/headbanner-1-8-1-12-with-gui.16/

Maven:
* Rebuild to Maven Project
=> Enable possibility of snapshots for MC 1.13

Internal:
* Updated code / removed deprecated methods partly
* Error fixing across multiple MC versions