The doc's indicate using gopkg.in, but that results in downlevel import from 2017

```console
$ go get gopkg.in/alessio/shellescape.v1
go: downloading gopkg.in/alessio/shellescape.v1 v1.0.0-20170105083845-52074bc9df61
go: added gopkg.in/alessio/shellescape.v1 v1.0.0-20170105083845-52074bc9df61

$ go get github.com/alessio/shellescape
go: downloading github.com/alessio/shellescape v1.4.2
go: added github.com/alessio/shellescape v1.4.2
```