update gradle

build.gradle

@@ -14,7 +14,7 @@ buildscript {
 
 plugins {
   // usage: gradle dependencyUpdates -Drevision=release
-  id "com.github.ben-manes.versions" version "0.27.0"
+  id "com.github.ben-manes.versions" version "0.28.0"
 }
 apply plugin: 'java'
 apply plugin: 'eclipse'
@@ -30,7 +30,7 @@ subprojects {
 	apply plugin: 'me.champeau.gradle.jmh'
 
 	// java compatibility version
-	sourceCompatibility = 10
+	sourceCompatibility = 11
 	
 	configurations {
 		tests
@@ -84,5 +84,5 @@ subprojects {
 }
 
 wrapper {
-	gradleVersion = '6.0.1'
+	gradleVersion = '6.5.1'
 }