install board in boards.txt.

    :param board_id: string identifier
    :param board_options: dict like
    :param replace_existing: bool
    :rtype: None

def install_board(board_id, board_options, hwpack='arduino', replace_existing=False):
    """install board in boards.txt.

    :param board_id: string identifier
    :param board_options: dict like
    :param replace_existing: bool
    :rtype: None

    """
    doaction = 0
    if board_id in boards(hwpack).keys():
        log.debug('board already exists: %s', board_id)
        if replace_existing:
            log.debug('remove board: %s' , board_id)
            remove_board(board_id)
            doaction = 1
    else:
        doaction = 1

    if doaction:
        lines = bunch2properties(board_id, board_options)
        boards_txt().write_lines([''] + lines, append=1)