cannot use Root literal

I'm totally new to go and installing things with go, but when I tried to install using

```
$ go get github.com/benbjohnson/ghfs/...
```

I get the following error:

```
$ go get github.com/benbjohnson/ghfs/... # github.com/benbjohnson/ghfs/cmd/ghfs
/Users/bparks/go/src/github.com/benbjohnson/ghfs/cmd/ghfs/main.go:62: cannot use Root literal (type *Root) as type fs.Node in return argument:
*Root does not implement fs.Node (wrong type for Attr method)
have Attr() fuse.Attr
want Attr(*fuse.Attr)
/Users/bparks/go/src/github.com/benbjohnson/ghfs/cmd/ghfs/main.go:82: cannot use User literal (type *User) as type fs.Node in return argument:
*User does not implement fs.Node (wrong type for Attr method)
```

I'm on a mac (10.8.5) and using zsh if it matters.... thanks!

Start in cmd/ghfs/main.go at the Root and User returns around lines 62 and 82, then inspect the fs.Node interface and the fuse.Attr method signature shown in the error. Confirm the compatibility issue by running go get github.com/benbjohnson/ghfs/...; done means the package installs without these compile errors.

Written by the indexing model from the issue text.