add Makefile for SK operator
add Makefile for SK operator

Darnor/SeminarDGL,El-Mono/SeminarDGL,AndreasFMueller/SeminarDGL,El-Mono/SeminarDGL,Darnor/SeminarDGL,crazycrank/SeminarDGL,AndreasFMueller/SeminarDGL,crazycrank/SeminarDGL