Update integration tests

samples/boot/redis-json/src/integration-test/java/sample/RedisSerializerTest.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.
@@ -39,7 +39,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 @SpringBootTest
 public class RedisSerializerTest {
 
-	private static final String DOCKER_IMAGE = "redis:5.0.1";
+	private static final String DOCKER_IMAGE = "redis:5.0.3";
 
 	@SpringSessionRedisOperations
 	private RedisTemplate<Object, Object> sessionRedisTemplate;