Add editor for gres.conf file

[NucciTheBoss]

The gres.conf file is used to configure GPUs in Slurm. Currently slurmutils doesn't have an editor for this file, but it will be necessary for if we want slurmutils to be capable of configuring Slurm to be GPU-aware in Charmed HPC.

Seems easy enough to model, but the one thing that will be interesting is that the configuration structure of this file seems to be much more flexible than the other Slurm configuration files. Some options can be defined both globally and in-line. The unique identifier for each line can either be NodeName or Name, and they can be used together. We might just want to pick a style and stick with it, but we'll need to ensure that the unit tests for the editor covers both cases.

[NucciTheBoss]

Related PR open here: charmed-hpc/slurmutils#37

[NucciTheBoss]

slurmutils 0.10.0 is now published to pypi. This release adds a gres.conf configuration file editor 😃