- Update the migrations tool to verify migrations work up and down for both MySQL and PostgresSQL.

- Add migrations for the squashed image tables and for backfilling the uncompressed sizes
- Make sure gzip stream uses a max length when determining the uncompressed size

data/model/legacy.py

@@ -13,7 +13,7 @@ from data.database import (User, Repository, Image, AccessToken, Role, Repositor
                            Notification, ImageStorageLocation, ImageStoragePlacement,
                            ExternalNotificationEvent, ExternalNotificationMethod,
                            RepositoryNotification, RepositoryAuthorizedEmail, TeamMemberInvite,
-                           random_string_generator, db, BUILD_PHASE)
+                           DerivedImageStorage, random_string_generator, db, BUILD_PHASE)
 from peewee import JOIN_LEFT_OUTER, fn
 from util.validation import (validate_username, validate_email, validate_password,
                              INVALID_PASSWORD_MESSAGE)