expose now returned purse_expiration in exchange API

src/include/taler_exchange_service.h

@@ -5192,6 +5192,7 @@ struct TALER_EXCHANGE_PurseGetResponse
      */
     struct
     {
+
       /**
        * Time when the purse was merged (or zero if it
        * was not merged).
@@ -5211,6 +5212,11 @@ struct TALER_EXCHANGE_PurseGetResponse
        */
       struct TALER_Amount balance;
 
+      /**
+       * Time when the purse will expire.
+       */
+      struct GNUNET_TIME_Timestamp purse_expiration;
+
     } success;
 
   } details;

src/lib/exchange_api_purses_get.c

@@ -109,6 +109,8 @@ handle_purse_get_finished (void *cls,
           &no_deposit),
         TALER_JSON_spec_amount_any ("balance",
                                     &dr.details.success.balance),
+        GNUNET_JSON_spec_timestamp ("purse_expiration",
+                                    &dr.details.success.purse_expiration),
         GNUNET_JSON_spec_fixed_auto ("exchange_pub",
                                      &exchange_pub),
         GNUNET_JSON_spec_fixed_auto ("exchange_sig",