Make it possible to run hyakvnc locally

[maouw]

Currently, hyakvnc must be run on a SLURM cluster. However, the containers themselves can work without a cluster, and it would be nice to be able to run hyakvnc locally for both general usage and testing. Currently, the help and config commands can run without SLURM being available. Perhaps this could be implemented through clever use of aliases and/or PATH in a manner similar to how mocking is implemented in shell testing frameworks like (e.g., bats). This would make testing much easier.