* FIX: Time slots compatibility with php 7.1
* ADD: Multi booking * ADD: Provider price * UPD: Integration with woocommerce * UPD: Notifications `Send Email` and `Call a Webhook`
* UPD: Admin panel for appointments * ADD: Ability to edit and add appointments from the admin panel * ADD: New views of appointments calendar and timeline. * ADD: Filter for searching and sorting appointments in the admin panel
