iluwatar#539 Checkstyle fixes

Author: iluwatar

balking/src/main/java/com/iluwatar/balking/WashingMachine.java

@@ -25,6 +25,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+ * Washing machine class
+ */
 public class WashingMachine {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(WashingMachine.class);

converter/src/main/java/com/iluwatar/converter/User.java

@@ -25,6 +25,9 @@
 
 import java.util.Objects;
 
+/**
+ * User class
+ */
 public class User {
   private String firstName;
   private String lastName;

converter/src/main/java/com/iluwatar/converter/UserDto.java

@@ -26,6 +26,9 @@
 
 import java.util.Objects;
 
+/**
+ * User DTO class
+ */
 public class UserDto {
 
   private String firstName;