The board of commissioners shall constitute the municipal government of such city, and shall be the successors of the mayor and council, and, upon the qualification of the members of said board of commissioners, all powers, rights, duties and emoluments of the then mayor and councilmen of any city adopting this act shall cease and terminate; but all current unfinished business shall proceed without interruption under the commissioners and all acts of the commissioners in respect thereto shall be valid in every respect.