Update release.gradle to be compatible with publish-plugin 1.3.0

Author: ryanjbaxter

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/gradle/release.gradle

@@ -56,22 +56,27 @@ if (isReleaseToCentral) {
 
 	apply plugin: 'com.gradle.plugin-publish'
 
-	pluginBundle {
+	gradlePlugin {
 		website = 'https://github.com/spring-cloud/spring-cloud-contract'
 		vcsUrl = 'https://github.com/spring-cloud/spring-cloud-contract'
 
 		plugins {
-			plugin {
+			springCloudContractPlugin {
 				id = 'org.springframework.cloud.contract'
 				displayName = 'spring-cloud-contract'
 				description = 'Spring Cloud Contract Gradle Plugin'
-				tags = ['spring', 'spring-framework', 'spring-cloud', 'spring-cloud-contract']
+				tags.set(['spring', 'spring-framework', 'spring-cloud', 'spring-cloud-contract'])
+				implementationClass = 'org.springframework.cloud.contract.verifier.plugin.SpringCloudContractVerifierGradlePlugin'
 			}
 		}
+	}
 
-		mavenCoordinates {
-			groupId = project.group
-			artifactId = project.name
+	publishing {
+		publications {
+			pluginMaven(MavenPublication) {
+				groupId = project.group
+				artifactId = project.name
+			}
 		}
 	}
 }