The current command used for alter a column (drop or alter) missing
the compatibility with sqllite. Solution, pass by using batch alembic.
Read http://alembic.readthedocs.org/en/latest/batch.html for more info.
Change-Id: I32c5cecaad111f2bde559de74ecefa339739b994
The length of keystone domain users is 64 chars length
but the columns that hold user_id were VARCHAR(36)
Change-Id: Idcbdd49b71ff3c88cf1801362b2f51d6cb22464e
Closes-Bug: #1521104