Add a callback to the initialized atlas state

def atlas_node_add_callback(atlas_state, callback_name, callback):
    """
    Add a callback to the initialized atlas state
    """
    if callback_name == 'store_zonefile':
        atlas_state['zonefile_crawler'].set_store_zonefile_callback(callback)

    else:
        raise ValueError("Unrecognized callback {}".format(callback_name))