Correct customer lifetime value calculation in customers

Signed-off-by: Wei-Chun, Chang <[email protected]>

models/customers.sql

@@ -41,6 +41,7 @@ customer_payments as (
     left join orders on
          payments.order_id = orders.order_id
 
+    where orders.status = 'completed'
     group by orders.customer_id
 
 ),