migration.db_sync requires an engine now

One of the migration test cases was still not passing an engine to
db_sync.  This doesn't show up in the gate because it is a negative
test that was failing with the correct exception for a different
reason.  I happened to find the problem because I had a file named
foo in my oslo-incubator directory from some previous testing and foo
was being passed in as the repository path, so that call wasn't
failing like it would on a clean system such as the gate.

Change-Id: Ia10cfbd4b99d821d9a725e6eb256fdd8ab001405
Mark files graduating to oslotest

Place clear markers at the top of the files that are moving
to oslotest. We shouldn't normally need to do this, but
not everything in the fixture directory moved.

Change-Id: Id05d4a069673b2d22b60868b7e5d6b19a5fa3b1a
Updated from global requirements

Change-Id: Ie13478a89c0eb227d0bb902dad19e984b83478fa
Merge "Mark files graduating to oslotest"
Merge "migration.db_sync requires an engine now"