Fix broken unit tests

After alembic update output of 'history' command in alembic changed

Closes-bug: #1396117
(cherry picked from commit 3bf970dffa218755ce3acedabca8d6d7eaf5b92b)

Conflicts:
	sahara/tests/unit/db/migration/test_migrations_base.py

Change-Id: I965250b25fc43a90a6df73316021f61b2a5e714d