Updated openstack/openstack
Project: openstack/nova  c5d23d45ecdc7717bf7fbcc1d50b0dda34cab2a0

Add EC2SnapshotMapping object

Create a nova object for the mappings between snapshot UUIDs and the
corresponding EC2 ID.

Part of blueprint convert-ec2-api-to-use-nova-objects

Change-Id: Ie29db77e404faff6ab9f12877094ea042e3c9924