Remove default title for Member

The default title for the Member class was removed. Previously, the title for every new Member was implicitly set to 'LORD'. Now it would require an explicit setting. This change has been prompted to meet the scenario where not all members may have 'LORD' as title, which improves flexibility.

src/main/java/got/Member.java

@@ -4,7 +4,7 @@
 
 public class Member implements Comparable<Member> {
     private Long id;
-    private Title title = Title.LORD;
+    private Title title;
     private String name;
     private LocalDate dob;
     private double salary;