install enum34 for certain python version (#700)
install enum34 for certain python version (#700)


google/openhtf,google/openhtf,jettisonjoe/openhtf,ShaperTools/openhtf,jettisonjoe/openhtf,jettisonjoe/openhtf,ShaperTools/openhtf,google/openhtf,ShaperTools/openhtf,ShaperTools/openhtf,google/openhtf,ShaperTools/openhtf,jettisonjoe/openhtf