fix: update go-git and go-billy to fix escaping on windows

Gopkg.lock

Gopkg.toml

vendor/gopkg.in/src-d/go-billy.v4/.gitignore

vendor/gopkg.in/src-d/go-billy.v4/.travis.yml

vendor/gopkg.in/src-d/go-billy.v4/README.md

vendor/gopkg.in/src-d/go-billy.v4/fs.go

vendor/gopkg.in/src-d/go-billy.v4/go.mod

vendor/gopkg.in/src-d/go-billy.v4/helper/chroot/chroot.go

...or/gopkg.in/src-d/go-billy.v4/helper/polyfill/polyfill.go

vendor/gopkg.in/src-d/go-billy.v4/osfs/os.go

vendor/gopkg.in/src-d/go-billy.v4/util/util.go

vendor/gopkg.in/src-d/go-git.v4/.gitignore

vendor/gopkg.in/src-d/go-git.v4/.travis.yml

vendor/gopkg.in/src-d/go-git.v4/blame.go

vendor/gopkg.in/src-d/go-git.v4/config/config.go

vendor/gopkg.in/src-d/go-git.v4/config/modules.go

vendor/gopkg.in/src-d/go-git.v4/config/refspec.go

vendor/gopkg.in/src-d/go-git.v4/go.mod

vendor/gopkg.in/src-d/go-git.v4/go.sum

vendor/gopkg.in/src-d/go-git.v4/object_walker.go