Every license granted under the provisions of this chapter shall at all times be subject to the provisions of this code, existing when the same shall be issued, or which shall thereafter be passed, so far as the same shall apply, and shall be subject to revocation by the mayor at any time upon failure of any person obtaining the same or any person in his employment to so conform to the provisions of this code. It shall be the duty of the chief of police or any policeman to report all violations of the holders of such licenses to the mayor, and in case such license shall be revoked, to see to it that such place of amusement, entertainment, performance or exhibition is closed. (R.O. 1959, Ch. 7, Art. 1, Sec. 7)