username 변경에 맞추어 수정

@@ -12,7 +12,7 @@ export const UserStatus: React.FC<UserStatusProps> = ({ user }) => {
                     user.ready ? 'text-green-500' : 'text-black'} 
                     text-lg text-center align-middle
                     ease-linear transition-all duration-100`}>
-                      {user.username}</div>
+                      {user.nickname}</div>
     </div>
   )
 }
\ No newline at end of file

@@ -7,17 +7,14 @@ export interface RoomData {
 
 export interface User {
   username: string;
+  nickname: string;
   admin: boolean;
   ready: boolean;
 }
 
 export interface UpdateRoomUser {
   state: "added" | "updated" | "removed";
-  user: {
-    username: string;
-    admin: boolean;
-    ready: boolean;
-  };
+  user: User;
 }
 
 export interface ChatData {

@@ -12,13 +12,13 @@ export const Login: React.FC = () => {
     const login = useCallback(() => {
       const rawMessage: RawMessage = {
         type: MessageType.LOGIN,
-        message: { username }
+        message: { nickname: username }
       }
-      socket.emit('msg', rawMessage, (response : MessageResponse<undefined>) => {
+      socket.emit('msg', rawMessage, (response : MessageResponse<string>) => {
         if (response.ok) {
           history.push({
             pathname: '/rooms',
-            state: { username: username }
+            state: { username: response.result }
           });
         } else {
           console.error('login error!'); // TODO: 팝업 에러?