Apparentely I0163e637ffef6d45d2573ebe29b5438911d01fce breaks Nova
tests, as we no longer provision a new DB in DatabaseResource by
default. While the recommended way is to use the new fixtures, we
should make sure the original behavior is preserved for the legacy
test cases.
Change-Id: I3e238b6a97769cf0a352f11e718d5d73eebcfa8a