Check for None or timestamp in availability zone api sample

test_availability_zone_detail depends on the services not having an
updated_at time set in the database.  This is set by a periodic task so
it's not guaranteed to be set, or not, shortly after the service starts.
On a fast system the test reliably passes, but adding a delay causes the
test to start failing.  Introducing a time.sleep(5) in the test seems to
make it reliably fail for me.  The test should pass if updated_at is set
to None or a timestamp.

Change-Id: I976ddf5354a52ca06a6419a92abcacb7d2379a37
Closes-bug: 1300810
Update user_id length to match Keystone schema in volume_usage_cache

Update the maximum length to match the Keystone schema for maximum
user_id length in volume_usage_cache. In the case that Keystone were
to leverage the full varchar 64, there would potentially be data loss
and/or collision of user_ids across records.

This change originates from the conversation about increasing the
length of user_ids in Keystone:

http://lists.openstack.org/pipermail/openstack-dev/2014-February/028125.html

Even with the length not changing, it is important to ensure there is no
loss of data/resolution when relying on user_id to identify users uniquely.

Closes-Bug: #1226171
Change-Id: I05a5644a29d6e2432311c2ee5331970d5e8b0683
Merge "Update user_id length to match Keystone schema in volume_usage_cache"
Merge "Check for None or timestamp in availability zone api sample"