[Autopilot] Need to implement tests for favourite mode

[Riccardo Padovani]

After the merge of [0]. we need some tests to check if favourite mode works well.

Some possible tests:
- Add a favourite
- Check if the favourite is in the bottom edge page
- Delete a favourite
- Check if the favourite isn't anymore in the bottom edge
- Check if after adding a favourite the next one isn't a favourite
- Check if text is saved correctly

And so on...
I leave this bug to bootstrap the environment (add vars in qml, basic autopilot functions and so on) then we can split single tests in single bugs

[0]: https://code.launchpad.net/~rpadovani/ubuntu-calculator-app/favouriteImplementation20150128/+merge/247900