'Increments the button label, sets bold so user knows there are
unread notifications'

def inc_notif_button_label(self):

    self.notif_button_label_int += 1
    child = self.notif_button.get_child()
    self.notif_button.remove(child)
    label = Gtk.Label.new()
    label.set_markup(('<b>    %s    %s    </b>' % (self.notif_text, str(self.notif_button_label_int))))
    label.show()
    self.notif_button.add(label)
