Sync models with migrations

Models should be the same as the state in DB after migration
blueprint db-sync-models-with-migrations

Change-Id: Iea57866206776c14677dfa78e868143b6fb153a9
Remove unused var DEFAULT_MAX_CACHE_SIZE

In file: glance/image_cache/__init__.py, DEFAULT_MAX_CACHE_SIZE
is never used after declared, remove it and make glance code
tidy and pleasing.

Change-Id: I208f1dc63e2bc95bb6be94fdc88f9bfce069f67c
Fix up trivial License mismatches

This makes the Hacking licensing check succeed.

Change-Id: Iba1446fa06fe466a05514d5df0e53d26dd9fc8e4
Fix useless assertTrue

In glance/tests/functional/test_scrubber.py,
TestScrubber::test_scrubber_with_metadata_enc(), local var marker_uri
is always not None, so self.assertTrue(marker_uri is not None) don't
make sense. This patch init it with None.

Change-Id: Id2fcffe6ff67b6fa59247d42ab15ffb228dd622f
Merge "Fix useless assertTrue"
Merge "Fix up trivial License mismatches"
Merge "Sync models with migrations"
Merge "Remove unused var DEFAULT_MAX_CACHE_SIZE"