add support to module loaders both client and serverside

[kilianc]

It would be nice to be able to require this library through requirejs or node.

[mseeley]

Ditto on requiring through node.

[jtenner]

I would love to even install this via yarn, but the lack of package.json prevents it.

I'm thinking about making a pull request with a simple package.json so it's possible to install via:

npm install --save jakesgordon/bin-packing

or with yarn via yarn add