provision/docker/flatten.go: logging when flatten succeeds
provision/docker/flatten.go: logging when flatten succeeds

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