Update MainMenuUnitTest.java

Updated the method name to follow BDD conventions

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exceptions/nosuchmethoderror/MainMenuUnitTest.java

@@ -7,7 +7,7 @@ import org.junit.jupiter.api.Test;
 class MainMenuUnitTest {
 
 	@Test
-	void testgetSpecials() {
+	void whenGetSpecials_thenNotNull() {
 		assertNotNull(MainMenu.getSpecials());
 	}