set attribute_maps to the neighbor.

def set_neighbor_attribute_map(neigh_ip_address, at_maps,
                               route_dist=None, route_family=VRF_RF_IPV4):
    """set attribute_maps to the neighbor."""
    core = CORE_MANAGER.get_core_service()
    peer = core.peer_manager.get_by_addr(neigh_ip_address)

    at_maps_key = const.ATTR_MAPS_LABEL_DEFAULT
    at_maps_dict = {}

    if route_dist is not None:
        vrf_conf =\
            CORE_MANAGER.vrfs_conf.get_vrf_conf(route_dist, route_family)
        if vrf_conf:
            at_maps_key = ':'.join([route_dist, route_family])
        else:
            raise RuntimeConfigError(desc='No VrfConf with rd %s' %
                                          route_dist)

    at_maps_dict[const.ATTR_MAPS_LABEL_KEY] = at_maps_key
    at_maps_dict[const.ATTR_MAPS_VALUE] = at_maps
    peer.attribute_maps = at_maps_dict

    return True