Update copyright year of changed files

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/cassandra/CassandraHealthContributorAutoConfigurationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/cassandra/CassandraReactiveHealthContributorAutoConfigurationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/redis/RedisHealth.java

@@ -28,7 +28,10 @@ import org.springframework.data.redis.connection.ClusterInfo;
  *
  * @author Phillip Webb
  */
-class RedisHealth {
+final class RedisHealth {
+
+	private RedisHealth() {
+	}
 
 	static Builder up(Health.Builder builder, Properties info) {
 		builder.withDetail("version", info.getProperty("redis_version"));

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/redis/RedisReactiveHealthIndicator.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ApplicationContextFactory.java

@@ -41,7 +41,7 @@ public interface ApplicationContextFactory {
 	 * A default {@link ApplicationContextFactory} implementation that will create an
 	 * appropriate context for the {@link WebApplicationType}.
 	 */
-	static ApplicationContextFactory DEFAULT = (webApplicationType) -> {
+	ApplicationContextFactory DEFAULT = (webApplicationType) -> {
 		try {
 			switch (webApplicationType) {
 			case SERVLET: