* Upgrade Django to 3.0 and other dependencies to recent versions
* Fix otp version contsraint
* Remove six dependency
* Resolve some warnings
* Fix failing tests
* Update django-countries
* Resolve all RemovedInDjango31Warnings in test suite
* Run isort
* Fix import
* Update PostgreSQL version on travis
* Add testmode-support-flag to SalesChannels
* Make saleschannels/testmode-warnings even more dangerous!
* Add warning for payment-methods that do support testmode but are being used in a non-testmode order caused by a saleschannel in a testmode-shop.
* Remove redundant testmode_supported-flag for WebshopSalesChannel
* Raise error on API when sales_channel does not support testmode
* Tests
* Fix style issue after merge
* Initial work on seating
* Add seat guids
* Add product_list_top
* CartAdd: Ignore item when a seat is passed
* Cart display
* product_list_top → render_seating_plan
* Render seating plan in voucher redemption
* Fix failing tests
* Add tests for extending cart positions with seats
* Add subevent_forms to docs
* Update schema, migrations
* Dealing with expired orders
* steps to order change
* Change order positions
* Allow to add seats
* tests for ocm
* Fix things after rebase
* Seating plans API
* Add more tests for cart behaviour
* Widget support
* Adjust widget tests
* Re-enable CSP
* Update schema
* Api: position.seat
* Add guid to word list
* API: (sub)event.seating_plan
* Vali fixes
* Fix api
* Fix reference in test
* Fix test for real
* Data model + Editor
* Cart and order management
* Rebase migrations
* Fix typos, add tests on cart handling
* Add tests for checkout and quotas
* Add API endpoints
* Validation of settings
* Front page tax display
* Voucher handling
* Widget foo
* Show correct net pricing
* Front page tests
* reverse charge foo
* Allow to require bundling
* Fix test failure on postgres
- [x] Data model
- [x] Enforce constraint
- [x] Filter order list
- [x] Set channel on created order
- [x] Products API
- [x] Order API
- [x] Tests
- [x] Filter reports
- [x] Resellers
- [ ] deploy plugins
- [ ] posbackend
- [ ] resellers
- [ ] reports
- [x] Ticketlayouts
- [x] Support in pretixPOS
