'Apprends a remove_terminal_icon to the end of notebooks
action area'

def append_remove_terminal_button_to_notebook(self):

    remove_terminal_icon = Gtk.Image.new_from_file((self.icons + 'exit.png'))
    remove_terminal_button = Gtk.Button()
    remove_terminal_button.set_tooltip_text('Delete    current    tab')
    remove_terminal_button.connect('clicked', self.delete_tab)
    remove_terminal_button.set_image(remove_terminal_icon)
    remove_terminal_button.set_relief(Gtk.ReliefStyle.NONE)
    remove_terminal_button.show()
    self.notebook.set_action_widget(remove_terminal_button, Gtk.PackType.END)
