fixes serialization unit test (#1837)

* adds serialization code

* fixes serialization unit test

core-java/src/main/java/com/baeldung/serialization/Person.java

@@ -0,0 +1,30 @@
+package com.baeuldung.serialization;
+import java.io.Serializable;
+
+public class Person implements Serializable {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = 1L;
+
+	private int age;
+	private String name;
+
+	public int getAge() {
+		return age;
+	}
+
+	public void setAge(int age) {
+		this.age = age;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+}