Karma config for the tests

Now that famous is available from a CDN, it has been possible to use karma for the tests.
I updated the old karma.conf.js file with the new dependencies.
You can test using `npm test` (don't forget to do a `npm install` and a `gulp build` before that).
Almost everything is failing since the tests haven't been updated for so long, but at least we have the basic test runner ! All we have to do now is write new tests (or update the existing ones).