* fix: replace `\` with `/` in git ref to fix `git_test.go` on windows
Paths on Windows use backslash (`\`) as directory separator and this breaks `TestGitFindRef()`.
Replacing `\` with `/` in git ref fixes that issue.
* fix: replace `gopkg.in/godo.v2/glob` with std library `path/filepath`
`github.com/go-godo/godo` lib has been last updated in 2016 and it also
depends on another outdated lib `github.com/MichaelTJones/walk` with
last update in 2016. This also fixes `permission_denied` errors on
Windows (and perhaps Linux in some specific cases). I'm not aware of
any performance improvement or drawback because of that change.