Removed unused import

Author: mechero

src/test/java/com/thepracticaldeveloper/objectmapperbasics/ObjectMapperBasicsTest.java

@@ -25,7 +25,6 @@
 import java.io.IOException;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;