Fix sqlalchemy utils test cases for SA 0.9.x

To be able to run migration scripts on SQLite we've been providing
a few workarounds for sqlalchemy-migrate and SQLAlchemy 0.7.x and
0.8.x branches in the form of sqlalchemy utils module. In 0.9.x
releases a few workarounds become obsolete (due to improvements made
to schema reflection for SQLite in SA), but our test cases still
expect SA to raise exceptions in several cases.

As long as our utils can work well with 0.9.x SA releases with our
workarounds and without them, we can just skip the test cases
expecting exceptions to be raised when SA version > 0.9.0 is used
and continue to run them for older releases of SA.

Closes-Bug: #1292284

Change-Id: Ie6cdb017b64b393cff43957b2047b5aae142d54e
Merge "Fix sqlalchemy utils test cases for SA 0.9.x"