error after go get

I got this error after go getting the package
```
$ go get gopkg.in/olebedev/go-duktape-fetch.v2

../../../gopkg.in/olebedev/go-duktape.v2/duktape.go:83: constant 18446744073709551615 overflows int
```

go version: go version go1.9 darwin/amd64