Set up end to end testing

End to end tests can now be written with Jasmine and can be tested using Protractor. This closes issue #5.

The tests have to be in the `test/e2e` folder and have to end with `Spec.js`. 

To be able to run the tests you have to have Protractor and selenium properly installed/set up. This should suffice:

    npm install -g protractor
    webdriver-manager update

Before running the tests you also have to start the selenium webdriver

    webdriver-manager start

Then the node server

    node static_server.js

And then you can run the tests with

    protractor protractor.conf.js