add shipment

lib/data/services/auth_imp.dart

@@ -47,7 +47,7 @@ class AuthServiceImp implements AuthService {
   }
 
   @override
-  Future<User> joinInvite(String userName) {
+  Future<void> joinInvite(String userName) {
     return authFb.joinInvite(userName);
   }
 

lib/data/services/auth_service.dart

@@ -7,7 +7,7 @@ abstract class AuthService {
   Future<AuthResult> signInWithSmsCode(String smsCode);
   Future<void> signout();
   Future<void> signup(String userName);
-  Future<User> joinInvite(String userName);
+  Future<void> joinInvite(String userName);
   Future<void> updateProfileName(String newUserName);
   Future<void> updatePreferredCurrency(String currency);
   Future<bool> hasInvite();