Booking API draft 0.6

Hi,

There's an updated draft of the booking API specification available for
review:

https://www.openactive.io/open-booking-api/EditorsDraft/index.html

Changes:

* fix incorrect versions of diagram
* explain how to book free events
* added section on refunds and cancellations
* new draft section on provision of terms and conditions
* various some clarifications

Any comments, please submit them here:

https://github.com/openactive/open-booking-api/issues

To move towards 0.7 the plan is to:

* document booking of facilities
* review booking of scheduled events

Cheers,

L.

-- 
Leigh Dodds, Data Infrastructure Programme Lead, theodi.org
@ldodds
The ODI, 65 Clifton Street, London EC2A 4JE