ES module support

[nunoarruda]

Hi @stewartlord ,

Thanks for the handy library, any chance you can make it importable as an ECMAScript module? Angular, for example, complains about CommonJS or AMD dependencies:

[1] WARNING in /Users/nunoarruda/repos/Pulse-Angular/src/app/profiles/profile-list/profile-list.component.ts depends on 'identicon.js'. CommonJS or AMD dependencies can cause optimization bailouts.
[1] For more info see: https://angular.io/guide/build#configuring-commonjs-dependencies

Here's why: https://angular.io/guide/build#configuring-commonjs-dependencies

[stewartlord]

If anyone would like to support a fork with this feature I would be happy to link to it from the README on this repo.