Update NPM dependencies, and add a David-badge

It wouldn't build using ``npm install`` beacuse of some peerDependency or some such, so I updated them.

BTW, any interest in a Grunt-based build instead of the .sh script? Maybe getting your dependencies via bower/npm instead of bundling them?

Another thing, are all the dependencies in use? Seems to be quite a lot of them for a relatively small project. In this PR I just did a ``npm install --save-dev`` for each of your existing dependencies. At least the karma launchers except for chrome are not in use, etc.