If I have `./foo.md` with `permalink: foo`, when I run `jekyll doctor`:

```text
Configuration file: /Users/parker/code/jekyll/tsite/_config.yml
       Deprecation: 'foo.md' uses relative permalinks which will be automatically deprecated in Jekyll v1.1.
       Deprecation: 'test/foo.md' uses relative permalinks which will be automatically deprecated in Jekyll v1.1.
       Deprecation: 'test/index.md' uses relative permalinks which will be automatically deprecated in Jekyll v1.1.
```