Slurmdbd startup improvements and support for any partition configuration options

What's Changed

• Slurm startup should be more reliable; the slurmdbd retarts now wait for the relevant port to become available, as the systemd unit just returns when the binary starts. (#129)
• Any desired partition parameters can now be set, see openhpc_slurm_partitions.partition_params (#130)

New Contributors

• @m-bull made their first contribution in #129

Full Changelog: v0.10.0...v0.11.0