You delete a campaign by sending an HTTP DELETE request to the campaigns resource.
Campaigns are not 'physically' deleted - instead, the (read-only)
status field is set to TERMINATED.
Only users with designated permissions can delete campaigns.
Once a campaign has its
statusset to TERMINATED, it no longer appears in the resource list returned from the Reading API. Tying to fetch/update the Campaign will result in a 404 Not Found error.