timestamp gets updated at buying

Handler/Buy.hs

@@ -51,7 +51,9 @@ postBuyR uId bId = do
             else do
               let price = quant * (beveragePrice bev)
               let sw = price > (userBalance user)
+              today <- liftIO $ return utctDay =<< getCurrentTime
               runDB $ do
+                update uId [UserTimestamp =. today]
                 update uId [UserBalance -=. price]
                 update bId [BeverageAmount -=. quant]
               checkAlert bId