add serial to upper option to prompt_for_test_start (#486)
add serial to upper option to prompt_for_test_start (#486)


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