Moving files to parent folder gives error

I'm trying to move files from a subfolder to `process.cwd()` but when I try, it gives an `ENOTEMPTY` error.

```
{ [Error: ENOTEMPTY, rename '/Users/wouter/Dev/project-templates/project-template/bin/']
errno: -66,
code: 'ENOTEMPTY',
path: '/Users/wouter/Dev/project-templates/project-template/bin/' }
```

It seems like it's trying to rename the cwd (as I'm testing the cli I'm working on in the `bin` folder directly). The same thing happens when I use `npm link` and test it in a newly created test directory.

@andrewrk am I missing a setting or something, or is this just not possible with `mv`?