mount nfs using NFS3 to avoid user map issues resulting in root with no read access

We found that we had to mount the NFS mounts using NFS3 as opposed to the default 4 due to user mapping issues (i.e. /etc/slurm/slurm.conf -> /cm/shared/apps/slurm/var/etc/slurm.conf is nobody:nobody, resulting in root with no read access)