DATACMNS-1508 - Guard test to run only on Java 8.

Java 9 introduced different class loaders so it's no longer possible to have a test that covers both setups.

src/test/java/org/springframework/data/util/KotlinReflectionUtilsUnitTests.java

@@ -16,10 +16,12 @@
 package org.springframework.data.util;
 
 import static org.assertj.core.api.Assertions.*;
+import static org.assertj.core.api.Assumptions.*;
 
 import java.net.URL;
 import java.net.URLClassLoader;
 
+import org.junit.Before;
 import org.junit.Test;
 
 import org.springframework.core.KotlinDetector;
@@ -33,6 +35,11 @@ import org.springframework.util.ReflectionUtils;
  */
 public class KotlinReflectionUtilsUnitTests {
 
+	@Before
+	public void before() {
+		assumeThat(Version.javaVersion()).isLessThan(Version.parse("9.0"));
+	}
+
 	@Test // DATACMNS-1508
 	public void classShouldLoadWithKotlin() {
 		assertThat(KotlinDetector.isKotlinPresent()).isTrue();