Version 1.1.3 fails in browser - Buffer is not defined

We wanted to use the package to create hashes in Chrome, but on initial testing it seems like this package doesn't work in the browser.

When attempting to import the package it fails with the error message:

```
Buffer is not defined
```

You can see an minimal example in this Code Sandbox:
https://codesandbox.io/s/x2xyrq2plp

Start with the minimal CodeSandbox reproduction and the package import path in createHash. Confirm the failure in Chrome, then trace the browser bundle's Buffer dependency; done means the package imports and creates hashes in Chrome without “Buffer is not defined”.

Written by the indexing model from the issue text.