After the dissolution of a partnership the authority of each partner to bind the firm, and the other rights and obligations of the partners continue, notwithstanding the dissolution, so far as may be necessary to wind up the affairs of the partnership, and to complete transactions begun but unfinished at the time of the dissolution, but not otherwise: Provided that the firm is in no case bound by the acts of a partner who has become bankrupt; but this proviso does not affect the liability of any person who has, after the bankruptcy, represented himself or herself or knowingly suffered himself or herself to be represented as a partner of the bankrupt.