1.1.0 + files not working

Version 1.1.0 doesn't work for me when using the new `files` option. Dirty repos are clean.

The bug? `multimatch` does seem to work on paths.

```
> var multimatch = require('multimatch')
> multimatch(['unicorn/foo/baz.js', 'cake', 'rainbows/baz'], ['*', '!cake']);
[]
```

Found the bug here
https://github.com/avajs/ava-codemods/commit/eb122c981514386e318e2b68479eccc8a9f809e7

Start with the reproduction using version 1.1.0 and the `files` option, then inspect the referenced avajs/ava-codemods commit for the suspected change. Verify behavior with a dirty repository and paths matching `multimatch`; done means the appropriate dirty paths are detected instead of returning a clean result.

Written by the indexing model from the issue text.