Update integration tests

samples/boot/websocket/src/test/java/sample/ApplicationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2018 the original author or authors.
+ * Copyright 2014-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,7 +52,7 @@ import static org.assertj.core.api.Assertions.assertThatThrownBy;
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
 public class ApplicationTests {
 
-	private static final String DOCKER_IMAGE = "redis:4.0.11";
+	private static final String DOCKER_IMAGE = "redis:4.0.12";
 
 	@Value("${local.server.port}")
 	private String port;