Page slug is marked as required with asterisk, but has no validation for it #117
Description
In the page creation form (admin/pages/new), the slug is marked as a required field. However, it is not validated against the NotBlank assertion.
Because the sylius_cms_shop_page_show route requires the slug, I'm suggesting that we do not allow the creation of a page without a slug.
I will provide a PR for it.