Fix full database test script to not fail randomly

- Switches database schema creation to alembic, which solves the MySQL issue (and makes sure we test migrations as well)
- Adds a few time.sleep(1) to work around MySQL's second-precision issue when adding items to queues and then immediately retrieving them
- Disables the storage proxy tests when running against non-SQLite databases, as it causes failures with the multiple process and multiple transactions
- Changes initdb to support only populating the database, as well as fixing a few small items around the test data when working with non-SQLite data

test/test_api_usage.py

@@ -3,6 +3,7 @@
 import unittest
 import datetime
 import logging
+import time
 import re
 import json as py_json
 
@@ -2041,8 +2042,8 @@ class TestDeleteRepository(ApiTestCase):
                      params=dict(repository=self.SIMPLE_REPO))
 
     # Add a build queue item for the repo and another repo.
-    dockerfile_build_queue.put([ADMIN_ACCESS_USER, 'simple'], '{}')
-    dockerfile_build_queue.put([ADMIN_ACCESS_USER, 'anotherrepo'], '{}')
+    dockerfile_build_queue.put([ADMIN_ACCESS_USER, 'simple'], '{}', available_after=-1)
+    dockerfile_build_queue.put([ADMIN_ACCESS_USER, 'anotherrepo'], '{}', available_after=-1)
 
     # Delete the repository.
     self.deleteResponse(Repository, params=dict(repository=self.SIMPLE_REPO))
@@ -2563,6 +2564,7 @@ class TestRepositoryNotifications(ApiTestCase):
                           params=dict(repository=ADMIN_ACCESS_USER + '/simple', uuid=uuid))
 
     # Ensure the item is in the queue.
+    time.sleep(1) # Makes sure the queue get works on MySQL with its second-level precision.
     found = notification_queue.get()
     self.assertIsNotNone(found)
     self.assertTrue('notification_uuid' in found['body'])