def upgrade():
    if not has_column(context, 'user', 'password_reset_token'):
        op.add_column('user', sa.Column('password_reset_token', sa.String))
def downgrade():
    if has_column(context, 'user', 'password_reset_token'):
        op.drop_column('user', 'password_reset_token')
def upgrade():
    if not has_column(context, 'user', 'password_reset_token_expiration'):
        op.add_column('user', sa.Column('password_reset_token_expiration', sa.DateTime))