remove protoc command from .travis.yml
remove protoc command from .travis.yml

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