Unit Testing Setup and some tests

Hey,

I added a basic testing setup with Karma, Mocha, Chai and SinonJS. The config is in karma.conf.js and test-main.js.
The current config uses PhantomJS and has autowatch enabled. The non-requireJS dependencies have to be added to the karma config, whereas the requireJS ones have to be added to test-main.js

Tests can be executed using
```console
grunt test
```
Coverage-reports are also created within the "coverage/" folder.

I also wrote some tests for array_helper and for cv_utils to showcase how the requireJS dependencies can be used and how tests have to be written for the module system to work.

I also added a short paragraph in the README on how to get the tests running and which tools are being used.