Previously the name of the application was ExtremeTuxRacer,
but it was changed to extremetuxracer. The application could
not be installed, so this should fix it.
This PR partly solves the issue #301 when it adds the navigation
testing for Gnome. It uses the keyboard combinations to cycle through
running applications and checks that applications could be switched
accordingly. It also tests that you can switch between workspaces
and that you can move an applications to another workspace.