Change Go 1.6.3 to 1.7.1 in build_branch.json
Change Go 1.6.3 to 1.7.1 in build_branch.json

supergiant/supergiant,maikelvl/supergiant,supergiant/supergiant,supergiant/supergiant,jordanrinke/supergiant,supergiant/supergiant,jordanrinke/supergiant,jordanrinke/supergiant,maikelvl/supergiant,jordanrinke/supergiant,supergiant/supergiant,maikelvl/supergiant,jordanrinke/supergiant,maikelvl/supergiant