Update copyright year to 2021.

Closes #1952

spring-data-rest-tests/spring-data-rest-tests-security/src/main/java/org/springframework/data/rest/tests/security/Order.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 the original author or authors.
+ * Copyright 2016-2021 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-data-rest-tests/spring-data-rest-tests-security/src/main/java/org/springframework/data/rest/tests/security/Person.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 the original author or authors.
+ * Copyright 2016-2021 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-data-rest-tests/spring-data-rest-tests-security/src/test/java/org/springframework/data/rest/tests/security/PreAuthorizedOrderRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2020 the original author or authors.
+ * Copyright 2013-2021 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-data-rest-tests/spring-data-rest-tests-security/src/test/java/org/springframework/data/rest/tests/security/SecuredPersonRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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-data-rest-tests/spring-data-rest-tests-security/src/test/java/org/springframework/data/rest/tests/security/SecurityConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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-data-rest-tests/spring-data-rest-tests-security/src/test/java/org/springframework/data/rest/tests/security/SecurityIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.