Downgrade database.

def downgrade():
    """Downgrade database."""
    op.drop_constraint(op.f('fk_access_actionsusers_user_id_accounts_user'),
                       'access_actionsusers', type_='foreignkey')
    op.drop_index(op.f('ix_access_actionsusers_user_id'),
                  table_name='access_actionsusers')
    op.create_foreign_key(u'fk_access_actionsusers_user_id_accounts_user',
                          'access_actionsusers', 'accounts_user', ['user_id'],
                          ['id'])
    op.drop_constraint(op.f('fk_access_actionsroles_role_id_accounts_role'),
                       'access_actionsroles', type_='foreignkey')
    op.drop_index(op.f('ix_access_actionsroles_role_id'),
                  table_name='access_actionsroles')
    op.create_foreign_key(u'fk_access_actionsroles_role_id_accounts_role',
                          'access_actionsroles', 'accounts_role', ['role_id'],
                          ['id'])