The Bioblend documentation is here: http://bioblend.readthedocs.io/en/latest/api_docs/galaxy/all.html. As far as I know, cluster configuration is not an API function.
Instead please see the latest administrator training resources here: https://github.com/galaxyproject/dagobah-training/. Search for "Slurm" to find the relevant exercises, sample configuration files, and other related resources.
Thanks! Jen, Galaxy team