It is possible to add a release through the Pivotal API (v3) ?
Got an email from the Pivotal team:
Yes it is possible to add releases through API. In Tracker, releases are just a 'type' of story. You can add a release by specifying the story_type 'release'. See the example below.
curl -H "X-TrackerToken: TOKEN" -X POST -H "Content-type: application/xml" -d "<story><story_type>release</story_type><name>Release Torpedos Phase 1 </name><requested_by>James Kirk</requested_by></story>" http://www.pivotaltracker.com/services/v3/projects/PROJECT_ID/stories