Add maven plugin (#109)

* Add maven publish plugin for jitpack

* Add sources and artifacts

* Add jitpack config

* Add test output

* Add workaround for JDK 15

* Add back comment

* Add permission by explicitly executing bash

* Remove resources from JAR

* Readd source

* Update script

* Make ensure-java 15 executable

* Make ensure-java 15 executable

* Add gradlew

* Add gradlew

* Update jitpack to jdk 16

* update comment

* Get sources jar task working

* Skip tests during building on jitpack

* Remove install clause

* Add install clause

* Move clause

* Add publish clause to build.gradle

* Add export to module info

* Add required transitive dependency

* Revert

* Revert export