Company links

**Todo:**
- [x] Add the partners
- [x] Devise them and make them token authenticable
- [x] Paper trail them
- [x] Add CRUD views
- [x] Assign tickets to partners
- [x] Add token authentication
- [x] Let them reserve their ticket

This mechanism is the same as for SKO. You send out a unique link to an organisation with X number of ticket. The organisation is then responsible to fill in all the information using the link. Only they click confirm on a ticket (per ticket confirmation seems best) that ticket cannot be changed anymore and the ticket link is send.