GH-22: Upgrade to Sonarqube plugin

Fixes GH-22 (https://github.com/spring-projects/spring-kafka/issues/22)

build.gradle

@@ -1,9 +1,3 @@
-description = "Spring Kafka"
-
-apply plugin: 'base'
-apply plugin: 'project-report'
-apply plugin: 'idea'
-
 buildscript {
 	repositories {
 		maven { url 'https://repo.spring.io/plugins-release' }
@@ -15,6 +9,16 @@ buildscript {
 	}
 }
 
+plugins {
+	id "org.sonarqube" version "1.2"
+}
+
+description = "Spring Kafka"
+
+apply plugin: 'base'
+apply plugin: 'project-report'
+apply plugin: 'idea'
+
 def docsDir = 'src/reference/asciidoc' // Will be default with newer asciidoctor plugin
 
 ext {
@@ -213,10 +217,8 @@ reference.dependsOn asciidoctor
 	it.onlyIf { "$System.env.NO_REFERENCE_TASK" != 'true' || project.hasProperty('ignoreEnvToStopReference') }
 }
 
-apply plugin: 'sonar-runner'
-
-sonarRunner {
-	sonarProperties {
+sonarqube {
+	properties {
 		property "sonar.jacoco.reportPath", "${buildDir.name}/jacoco.exec"
 		property "sonar.links.homepage", linkHomepage
 		property "sonar.links.ci", linkCi