Revert "BAEL-4134"

persistence-modules/redis/src/main/java/com/baeldung/CustomMessage.java

@@ -1,9 +1,11 @@
 package com.baeldung;
 
+import java.io.Serializable;
+
 /**
  * Created by johnson on 3/9/17.
  */
-public class CustomMessage {
+public class CustomMessage implements Serializable {
     private String message;
 
     public CustomMessage() {

persistence-modules/redis/src/main/java/com/baeldung/Ledger.java

@@ -1,6 +1,8 @@
 package com.baeldung;
 
-public class Ledger {
+import java.io.Serializable;
+
+public class Ledger implements Serializable {
 
     public Ledger() {
     }