Make Kotlin language as 1.3 for SF compatibility

* Fix Checkstyle violation
* Bring back SNAPSHOT versions for Spring deps

Author: artembilan

build.gradle

@@ -98,12 +98,12 @@ ext {
 	smackVersion = '4.3.5'
 	soapVersion = '1.4.0'
 	springAmqpVersion = project.hasProperty('springAmqpVersion') ? project.springAmqpVersion : '2.3.6'
-	springDataVersion = project.hasProperty('springDataVersion') ? project.springDataVersion : '2021.0.0-M5'
-	springKafkaVersion = '2.7.0-RC1'
+	springDataVersion = project.hasProperty('springDataVersion') ? project.springDataVersion : '2021.0.0-SNAPSHOT'
+	springKafkaVersion = '2.7.0-SNAPSHOT'
 	springRetryVersion = '1.3.1'
-	springSecurityVersion = project.hasProperty('springSecurityVersion') ? project.springSecurityVersion : '5.5.0-M3'
-	springVersion = project.hasProperty('springVersion') ? project.springVersion : '5.3.5'
-	springWsVersion = '3.1.0-M2'
+	springSecurityVersion = project.hasProperty('springSecurityVersion') ? project.springSecurityVersion : '5.5.0-SNAPSHOT'
+	springVersion = project.hasProperty('springVersion') ? project.springVersion : '5.3.6-SNAPSHOT'
+	springWsVersion = '3.1.0-SNAPSHOT'
 	tomcatVersion = '9.0.44'
 	xmlUnitVersion = '2.8.2'
 	xstreamVersion = '1.4.16'
@@ -203,7 +203,10 @@ configure(javaProjects) { subproject ->
 
 	compileKotlin {
 		kotlinOptions {
+			languageVersion = '1.3'
 			jvmTarget = '1.8'
+			freeCompilerArgs = ['-Xjsr305=strict']
+			allWarningsAsErrors = true
 		}
 	}
 	compileTestKotlin {

spring-integration-jms/src/test/java/org/springframework/integration/jms/request_reply/RequestReplyScenariosWithTempReplyQueuesTests.java

@@ -111,9 +111,8 @@ public void messageCorrelationBasedOnRequestCorrelationIdTimedOutFirstReply() th
 			RequestReplyExchanger gateway = context.getBean(RequestReplyExchanger.class);
 			ConnectionFactory connectionFactory = context.getBean(ConnectionFactory.class);
 
-			final Destination requestDestination = context.getBean("siOutQueue", Destination.class);
+			Destination requestDestination = context.getBean("siOutQueue", Destination.class);
 
-			;
 			dmlc.setConnectionFactory(connectionFactory);
 			dmlc.setDestination(requestDestination);
 			dmlc.setMessageListener((SessionAwareMessageListener<Message>) (message, session) -> {