add combrionix command to get serial number
add combrionix command to get serial number

jettisonjoe/openhtf,jettisonjoe/openhtf,ShaperTools/openhtf,fahhem/openhtf,ShaperTools/openhtf,fahhem/openhtf,ShaperTools/openhtf,google/openhtf,ShaperTools/openhtf,ShaperTools/openhtf,google/openhtf,google/openhtf,fahhem/openhtf,amyxchen/openhtf,jettisonjoe/openhtf,fahhem/openhtf,grybmadsci/openhtf,grybmadsci/openhtf,amyxchen/openhtf,grybmadsci/openhtf,google/openhtf,jettisonjoe/openhtf,grybmadsci/openhtf