Update ack to version 2.18
Update ack to version 2.18

vinaynambiar/lukesampson-,rasa/scoop,vidarkongsli/scoop,lukesampson/scoop,Cyianor/scoop,reelsense/scoop,yunspace/scoop,nueko/scoop,toxeus/scoop,r15ch13/scoop,nikolasd/scoop,kodybrown/scoop,berwyn/scoop,Congee/scoop,coonce/scoop