'Defines what happens when the user clicks on the notifications
button: just show a silly window with a treeview containing
all the notifications'

def on_click_notifications(self, button):

    notifications_view = Gtk.TreeView(self.notificationsModel)
    renderer = Gtk.CellRendererText()
    column = Gtk.TreeViewColumn('Notifications', renderer, text=0)
    notifications_view.append_column(column)
    notifications_dialog = NotificationsDialog(notifications_view, self.delete_notifications, self.window)
    notifications_dialog.show_all()
