ksdme/paytm-gateway-checksums

Utility to generate and check Paytm Gateway integration checksums.

A readable and maintainable version of https://github.com/Paytm-Payments/Paytm_App_Checksum_Kit_NodeJs/blob/master/paytm/checksum.js.

Example
```
const checksum = require('paytm-gateway-checksums');

// This method also takes an optional third parameter which when
// true indicates that the parameters passed represent a refund.
checksum.generateCheckSum(parameters, MERCHANT_KEY)
  .then((sum) => console.log(sum))
  .catch((error) => console.error(error));
```