Specs failing on Windows

I just cloned the [git-utils](https://github.com/atom/git-utils) repo (with `--recurse`) and did the following steps:

```
npm install
grunt
grunt test
```

and I got the following errors:

![git-utils-tests](https://cloud.githubusercontent.com/assets/2007045/6027401/0e92d21a-ab9f-11e4-9e06-44dca68d0fb9.png)
