Adding a first unit test to the angularjs footer

I have evaluated where I would need to place the `js` files in the
`test` folder and see that when running `grunt test` also work (as it
would work with `npm test`.
The `karma.conf.js`, the configuration file for the testing framework,
was also modified to avoid one of the folders that it tries to
identifies (`/test/mock/**/*.js/`) and remove that annoying warning
that I get when testing