Merge #9 and release v2.2

Release v2.1.0 - compatibility with Gradle 7+

v2.0.0 - needed for Gradle 6.4+

Re-adds the ability to rely on an already downloaded Gradle via `gradlew` execution, on top of #4 for better convenience even if breaking backwards compatibility

Adds Commons CLI and JUnit to the classpath and includes a couple tes…

…ts! Fixes #2

Release v1.0.1

Add docs and stuff