Include git head in version number

Author: WiIIiam278

build.gradle

@@ -1,10 +1,11 @@
 plugins {
     id 'java'
     id 'com.github.johnrengelman.shadow' version '7.1.2'
+    id 'org.ajoberstar.grgit' version '5.0.0'
 }
 
 group 'net.william278'
-version '2.0'
+version "2.0-${versionMetadata()}"
 
 repositories {
     mavenCentral()
@@ -37,4 +38,12 @@ jar {
 
 test {
     useJUnitPlatform()
+}
+
+@SuppressWarnings('GrMethodMayBeStatic')
+def versionMetadata() {
+    if (grgit == null) {
+        return System.getenv("GITHUB_RUN_NUMBER") ? 'build.' + System.getenv("GITHUB_RUN_NUMBER") : 'unknown'
+    }
+    return grgit.head().abbreviatedId + (grgit.status().clean ? '' : '-indev')
 }