NFS mount option - for non-plugin systems

[mjstealey]

SciDAS infrastructure does not support docker based plugin's on the nodes, so an alternate means of shared storage should be implemented to demonstrate how to incorporate volume sharing between containers.

• volume sharing via NFS mounts internal to the container build
• client integration as part of slurm base image
• logic to be part of entry point code using environment variables to configure at runtime
• provide demo NFS server container as part of distribution with documentation