provision/docker: use workers in unit-add
provision/docker: use workers in unit-add

Related to #1149.

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