Removed acceptance tests.

Testing error alerts for the tour is too tricky and not too important. Removing them for now.
Use helper function instead of manually accessing the DOM to close tour.
Use a helper function instead of directly accessing the DOM to complete a tour.
Added acceptance test.
Changed variable name.

It actually is a media query to select widths under the sm cutoff, that is, widths that belong to the xs- responsive Bootstrap category.
The main app tour is only shown if the screen is bigger than a smartphone (sm bootstrap responsive category or bigger).

A different tour will be shown in smartphones.