grgit gradle plugin to get current version

See doc at https://ajoberstar.org/grgit/grgit-describe.html

1. First time

./gradlew getVersion

> Task :getVersion
SNAPSHOT VERSION 0.0.0.7526fa4

2. We add a tag

git tag 1.0.0
./gradlew getVersion

> Task :getVersion
RELEASED VERSION 1.0.0

3. We add another commit

git commit --allow-empty -m "Another commit"
./gradlew getVersion

> Task :getVersion
SNAPSHOT VERSION 1.0.0.99cb359

2. We add another tag

git tag 1.0.1
./gradlew getVersion

> Task :getVersion
RELEASED VERSION 1.0.1