A commissioner of the Urban Renewal Authority shall receive no compensation for his services, but shall be entitled to the necessary expenses, including travel expenses, incurred in the discharge of his duties. Each commissioner shall hold office until his successor has been appointed and qualified. A certificate of appointment or reappointment of any commissioner shall be filed with the City Clerk and shall be conclusive evidence of the due and proper appointment of such commissioner. (1969 Code Sec. 2-82)