Fix suffix of test classes names

As per Spring Framework code style [1], the suffix of
test classes should be "Tests". This commit fixes that
for some classes that do not conform to the code style.

[1]: https://github.com/spring-projects/spring-framework/wiki/Code-Style#tests

spring-batch-test/src/test/java/org/springframework/batch/test/context/BatchTestContextCustomizerFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 the original author or authors.
+ * Copyright 2018-2021 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.
@@ -27,7 +27,7 @@ import org.springframework.test.context.ContextCustomizer;
 /**
  * @author Mahmoud Ben Hassine
  */
-public class BatchTestContextCustomizerFactoryTest {
+public class BatchTestContextCustomizerFactoryTests {
 
 	private BatchTestContextCustomizerFactory factory = new BatchTestContextCustomizerFactory();
 

spring-batch-test/src/test/java/org/springframework/batch/test/context/BatchTestContextCustomizerTests.java

@@ -29,7 +29,7 @@ import static org.hamcrest.MatcherAssert.assertThat;
 /**
  * @author Mahmoud Ben Hassine
  */
-public class BatchTestContextCustomizerTest {
+public class BatchTestContextCustomizerTests {
 
 	private BatchTestContextCustomizer contextCustomizer = new BatchTestContextCustomizer();