travis-ci: Fail if any applet or tool needed for tests fails to build
travis-ci: Fail if any applet or tool needed for tests fails to build

(in our case, it was yubico-piv-tool and PivApplet for some time)

AktivCo/OpenSC,frankmorgner/OpenSC,hongquan/OpenSC-main,rickyepoderi/OpenSC,OpenSC/OpenSC,frankmorgner/OpenSC,Jakuje/OpenSC,LudovicRousseau/OpenSC,hongquan/OpenSC-main,fabled/OpenSC,Jakuje/OpenSC,mouse07410/OpenSC,philipWendland/OpenSC,rickyepoderi/OpenSC,AktivCo/OpenSC,LudovicRousseau/OpenSC,OpenSC/OpenSC,hongquan/OpenSC-main,AktivCo/OpenSC,dengert/OpenSC,rickyepoderi/OpenSC,fabled/OpenSC,mouse07410/OpenSC,philipWendland/OpenSC,dengert/OpenSC,LudovicRousseau/OpenSC,fabled/OpenSC,metsma/OpenSC,dengert/OpenSC,metsma/OpenSC,OpenSC/OpenSC,Jakuje/OpenSC,frankmorgner/OpenSC,Jakuje/OpenSC,metsma/OpenSC,frankmorgner/OpenSC,mouse07410/OpenSC,philipWendland/OpenSC,fabled/OpenSC