v0.4.0

Added

• ExportFactory which integrates spatie/laravel-export
  • \Astrotomic\Stancy\Contracts\ExportFactory
  • \Astrotomic\Stancy\Facades\ExportFactory
  • \Astrotomic\Stancy\Factories\ExportFactory
• \Astrotomic\Stancy\Models\Page::getUrl() method which depends on \Astrotomic\Stancy\Contracts\Routable interface