Borrel reservations

[KiOui]

This pull request adds a borrel application to TOSTI which replaces the functions of the VoorraadCie website. The functions of the application include:

• Keeping track of people with a BasicBorrelBrevet
• Enabling people with a BasicBorrelBrevet to create ReservationRequests
• Enabling VoorraadCie members to respond to these ReservationRequests
• Enabling people with a BasicBorrelBrevet to track their ReservationRequests and see whether they are accepted
• Enabling people with a BasicBorrelBrevet to digitally hand in a BorrelForm
• Enabling VoorraadCie members to add and remove Products from the BorrelForm and their inventory

Closes #169

[KiOui]

Things still TODO:

• Create BorrelProduct model
• Create a BorrelProductCategory model
• Create a BorrelForm model
• Create a BorrelInventoryRequest model which stores BorrelProducts and their respective ordered amounts
• Add a way for creating a BorrelInventoryRequest to a ReservationRequest on the ReservationRequestCreateView
• Add verifiers to the ReservationRequestCreateView (such as filtering reservations that are in the past)
• Add a way for users to see their ReservationRequests and the responses to these ReservationRequests
• Add administrator actions for accepting and denying ReservationRequests which should automatically create a Reservation (in case of accepting)
• Add buttons on the respective pages to create a ReservationRequest
• Add a way for users with a BasicBorrelBrevet to enter their BorrelForms digitally
• Squash migrations

[KiOui]

Example borrel form

[JobDoesburg]

You should use Django's inlineformset_factory's to add inline items to the reservation form to add reserved items

[KiOui]

This needs to be changed as a whole when #174 is merged.

[JobDoesburg]

I doubt if this venue calendar thing is the best way to separate modules. I think it is best to have borrel depend on the venue calendar app, and add one of those nice filters to display the kind of reservations that can be made for this calendar and add the buttons for it.

[JobDoesburg]

TODO:

• Display form and non-form error messages correctly in the template
• Use correct success redirects and user-messages
• Improve page structure (menu items, buttons, etc)
• Implement the logic on when to use ReservationSubmission and ReservationUpdate views, when to show buttons and when to allow access to the view
• Implement something to check out submitted borrel lists as read only objects
• Deleting reservation items (hit the DELETE checkbox if 0 is entered)
• Fix the calendar (currently, nothing shows up in the calendar)
• Better link borrel and venue reservations
• Venue reservations page and explainer
• Give other people access to your borrel reservation (maybe with UUID's?)
• Approval for changing reservations (if people change their reservation, this should be approved? Can they even change?)
• Notification emails
• Cancelling / deleting reservations (borrel ánd venue)
• Test if the form breaks with changing available products
• Display current venue reservation on home page, maybe do something with music controls

[KiOui]

When reserving a Venue, I get this error: