re-add clang builds to travis
re-add clang builds to travis

pmprog/OpenApoc,Istrebitel/OpenApoc,FranciscoDA/OpenApoc,Istrebitel/OpenApoc,FranciscoDA/OpenApoc,steveschnepp/OpenApoc,pmprog/OpenApoc,steveschnepp/OpenApoc,ShadowDancer/OpenApoc,ShadowDancer/OpenApoc,FranciscoDA/OpenApoc