Adding gres handling for teach

[yassinkhalifa]

Adding srun's gres parameter handling logic for teach in order to pass the requested gres and set the default num_gpus if not requested when c=teach and p=gpu

[chnixi]

Still doesn't seem to work, same issue as before:

[chx33@login0 ~]$ crc-interactive -e -p gpu
[chx33@teach-gpu-n0 ~]$ nvidia-smi
No devices were found

[yassinkhalifa]

@chnixi This hasn't been installed to the cluster yet Chen. I'll let you know once this is done.