Create instance with deleting image

If we attempt to create a new instance with an image that has just now
been deleted in glance, (ie. status="DELETED", but deleted=False).

The server should throw a 4XX error rather than a 5XX error.

This commit just adds tests.

Tests bug 1155458
Change-Id: Ifae470e96ddc4526ef67581a1d7171ccc5fd32b7
Merge "Create instance with deleting image"