message: Using batch_op in db migration
  As I needed to downgrade from db migration I realized I
  needed to use batch_op against SQLLite.
diff: @@ -14,8 +14,10 @@ down_revision = '55e910a74826'
  def upgrade():
  - op.add_column('query', sa.Column('extra_json', sa.Text(), nullable=True))
  + with op.batch_alter_table('query') as batch_op:
  + batch_op.add_column(sa.Column('extra_json', sa.Text(), nullable=True))
  def downgrade():
  - op.drop_column('query', 'extra_json')
  + with op.batch_alter_table('query') as batch_op:
  + batch_op.drop_column('extra_json')
  