fix core-java test and back to build

core-java/pom.xml

@@ -13,6 +13,7 @@
         <relativePath>../parent-java</relativePath>
     </parent>
 
+
     <dependencies>
         <dependency>
             <groupId>commons-io</groupId>

core-java/src/test/java/com/baeldung/leapyear/LeapYearUnitTest.java

@@ -1,6 +1,8 @@
 package com.baeldung.leapyear;
 
+import java.time.LocalDate;
 import java.time.Year;
+import java.time.format.DateTimeFormatter;
 import java.util.GregorianCalendar;
 
 import org.junit.Assert;