Add WebSocket testing

[wzr1337]

We need to add tests for WebSockets. Subscriptions etc.

like this:

describe('general WebSocket Test', () => {

  it('Should receive an acknowledgement on subscription', (done: DoneFn) => {
    wsTest('/some/resource/').subscribe((data) => {
        expect(data).not.toBeUndefined();
   })
    done();
  });

});

[wzr1337]

we can base of https://github.com/INRIX-paul-boyes/ws-test maybe