v0.3.1

Migration from 0.3.0

This release contains a breaking wire rename.

• Calling SDK requests now use x-abto-feature-id; the Gateway no longer accepts x-abto-node-key.
• Event SDK context now uses $feature_id instead of $node_key.
• Update the affected SDK and Gateway contract together before deploying.

Full Changelog: v0.3.0...v0.3.1