store: postgres
attempt 1: client gave up after 300 ms (the server is still working)
attempt 2, 300 ms later            -> HTTP 201  replayed=true retry-after=-    {"id":1,"customer":"cus_42","amount":1999,"currency":"INR"}
attempt 3, after the first finished -> HTTP 201  replayed=true retry-after=-    {"id":1,"customer":"cus_42","amount":1999,"currency":"INR"}
payments in the table: 1