No need to apply java and groovy plugins when we depend on groovy-gra…

…dle-plugin

build.gradle

@@ -1,12 +1,9 @@
 plugins {
-    id 'java-gradle-plugin'
+    id 'groovy-gradle-plugin'
     id 'maven-publish'
     id 'com.gradle.plugin-publish' version '0.15.0'
 }
 
-apply plugin: 'groovy'
-apply plugin: 'java'
-
 apply from: "$rootDir/gradle/gradle-plugin-publishing.gradle"
 
 // To publish, use these tasks: