testing: simplifying fakeprovisioner ExecuteCommandOnce.
testing: simplifying fakeprovisioner ExecuteCommandOnce.

tuxmonteiro/tsuru,tsuru/tsuru,jblancett/tsuru,mderaldo/tsuru,cezarsa/tsuru,kgrvamsi/tsuru,gwmoura/tsuru,hcxiong/tsuru,tuxmonteiro/tsuru,kgrvamsi/tsuru,gciotta/tsuru,tuxmonteiro/tsuru,hcxiong/tsuru,cgvarela/tsuru,Endika/tsuru,ArxdSilva/tsuru,cezarsa/tsuru,ggarnier/tsuru,ArxdSilva/tsuru,cgvarela/tsuru,ggarnier/tsuru,cezarsa/tsuru,tsuru/tsuru,4eek/tsuru,firebitsbr/tsuru,jblancett/tsuru,ArxdSilva/tsuru,gciotta/tsuru,RichardKnop/tsuru,guilhermebr/tsuru,firebitsbr/tsuru,cezarsa/tsuru,gwmoura/tsuru,hugoantunes/tsuru,ggarnier/tsuru,RichardKnop/tsuru,hugoantunes/tsuru,Endika/tsuru,Endika/tsuru,mderaldo/tsuru,4eek/tsuru,gwmoura/tsuru,cgvarela/tsuru,4eek/tsuru,tsuru/tsuru,kgrvamsi/tsuru,jblancett/tsuru,tsuru/tsuru,hcxiong/tsuru,guilhermebr/tsuru,guilhermebr/tsuru,guilhermebr/tsuru,gciotta/tsuru,firebitsbr/tsuru,mderaldo/tsuru,ArxdSilva/tsuru,RichardKnop/tsuru,ggarnier/tsuru