ENH: Build ComputeTrainingMask even without VTK
ENH: Build ComputeTrainingMask even without VTK

thewtex/TubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/TubeTK,sumedhasingla/TubeTK,sumedhasingla/TubeTK,aylward/ITKTubeTK,thewtex/TubeTK,aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,thewtex/TubeTK,cdeepakroy/TubeTK,sumedhasingla/TubeTK,KitwareMedical/TubeTK,aylward/ITKTubeTK,cdeepakroy/TubeTK,aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,sumedhasingla/TubeTK,cdeepakroy/TubeTK,KitwareMedical/TubeTK,KitwareMedical/TubeTK,cdeepakroy/TubeTK,thewtex/TubeTK,KitwareMedical/ITKTubeTK