Upgrade dependencies; prepare for release

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-	ext.kotlinVersion = '1.3.21'
+	ext.kotlinVersion = '1.3.30'
 	repositories {
 		maven { url 'https://repo.spring.io/plugins-release' }
 	}
@@ -15,8 +15,8 @@ plugins {
 	id 'base'
 	id 'project-report'
 	id 'idea'
-	id 'org.asciidoctor.convert' version '1.5.9.2'
-	id 'org.ajoberstar.grgit' version '3.0.0'
+	id 'org.asciidoctor.convert' version '1.5.10'
+	id 'org.ajoberstar.grgit' version '3.1.1'
 }
 
 description = 'Spring Kafka'
@@ -80,11 +80,11 @@ subprojects { subproject ->
 		junitPlatformVersion = '1.4.1'
 		kafkaVersion = '2.0.1'
 		log4jVersion = '2.11.2'
-		mockitoVersion = '2.25.1'
+		mockitoVersion = '2.26.0'
 		scalaVersion = '2.11'
 		springRetryVersion = '1.2.4.RELEASE'
-		springVersion = '5.1.6.RELEASE'
-		springDataCommonsVersion = '2.1.6.RELEASE'
+		springVersion = '5.1.7.RELEASE'
+		springDataCommonsVersion = '2.1.7.RELEASE'
 
 		idPrefix = 'kafka'
 
@@ -93,7 +93,7 @@ subprojects { subproject ->
 	eclipse.project.natures += 'org.springframework.ide.eclipse.core.springnature'
 
 	jacoco {
-		toolVersion = '0.8.2'
+		toolVersion = '0.8.3'
 	}
 
 	// dependencies that are common across all java projects
@@ -131,7 +131,7 @@ subprojects { subproject ->
 
 	checkstyle {
 		configFile = file("${rootDir}/src/checkstyle/checkstyle.xml")
-		toolVersion = "8.18"
+		toolVersion = "8.20"
 	}
 
 	jacocoTestReport {