flip stripeServer's parameters

let more "fixed" parameters come first and then the dynamic ones so
that one can do currying with the immutable parameters applied.

src/PaymentServer/Processors/Stripe.hs

@@ -101,8 +101,8 @@ getVoucher (MetaData []) = Nothing
 getVoucher (MetaData (("Voucher", value):xs)) = Just value
 getVoucher (MetaData (x:xs)) = getVoucher (MetaData xs)
 
-stripeServer :: VoucherDatabase d => d -> StripeSecretKey -> Server StripeAPI
-stripeServer d key = webhook d
+stripeServer :: VoucherDatabase d => StripeSecretKey -> d -> Server StripeAPI
+stripeServer key d = webhook d
                      :<|> charge d key
 
 -- | Process charge succeeded events

src/PaymentServer/Server.hs

@@ -42,7 +42,7 @@ type PaymentServerAPI
 -- | Create a server which uses the given database.
 paymentServer :: VoucherDatabase d => ByteString -> Issuer -> d -> Server PaymentServerAPI
 paymentServer key issuer database =
-  stripeServer database key
+  stripeServer key database
   :<|> redemptionServer issuer database
 
 paymentServerAPI :: Proxy PaymentServerAPI