7-1-4115. Procedure to advance municipal classification. (1) If it appears by such census that the city or town contains the requisite population to be advanced, the council must thereupon by resolution declare, as the case may be, that:

(a) the town is advanced to a city of the first, second, or third class;

(b) a city of the third class is advanced to a city of the second or first class; or

(c) a city of the second class is advanced to a city of the first class.

(2) The city or town council must file a certified copy of such resolution in the office of the county clerk of the county and in the office of the secretary of state. Whereupon such town becomes a city of the first, second, or third class; a city of the third class becomes a city of the second or first class; and a city of the second class becomes a city of the first class, as the case may be, to be governed under the provisions of this code relative to cities and towns.