Strong parameters

I needed to set permit to allow the params for seo.  Just a documentation issue.  for some reason explicitly setting allowed items:

`:seo_meta_attributes => []`

did not work  - seo_meta_attributes was still a unpermitted attribute.  so i strong armed it, I guess less secure but its in the cms, so maybe ok:

```
controller do
  def permitted_params
    params.permit!
end
```
