travis: enable build on Python nightly
travis: enable build on Python nightly

qPCR4vir/orange3,qPCR4vir/orange3,qPCR4vir/orange3,cheral/orange3,qPCR4vir/orange3,qPCR4vir/orange3,cheral/orange3,cheral/orange3,cheral/orange3,cheral/orange3,qPCR4vir/orange3,cheral/orange3