added package.json file for use with npm

[feelic]

Hi,

I created a package.json file for your lib to make it useable with npm in other projects
thanks for your work :)

Feelic

[benflodge]

Adding this file to the project would be very convenient!
I will use a forked version of this repo until there is a package.json added.
By merging this pull request you will also be able to close #9 however i don't think anyone is bothered about adding a bower.json anymore.