Panini error: you must specify a directory for layouts.

Above error occurs everytime I want to use my Panini task.
For the record, I installed it in my own Gulpy workflow.

I've tried changing the paths etc. but nothing worked.

Here's the task code:
```
function panini(){
return gulp.src('src/pages/**/*.html')
.pipe(panini({
root: 'src/pages/',
layouts: 'src/layouts/',
partials: 'src/partials/',
helpers: 'src/helpers/',
data: 'src/data/'
}))
.pipe(gulp.dest('build'));
}
```

My folder structure is the following:

```
src/
data/
helpers/
layouts/
- default.html
pages/
- index.html
partials/
img/
js/
scss/
```