Refactoring

I did a couple of changes:
1) now the server response is stored in a field of the task. So now tasks extending RestTask can use that field to do something based on the response.
2) I changed the unit tests so that they don't expect response.getData anymore
3) while doing that I noticed that the test about the authentication wasn't working as intended (it was skipping the whole "then" part), so i changed it