Add node name to JSON data per run

[j-woz]

I think Rajeev is looking at this.

[rajeeja]

Option are to use:

1. os.getpid
2. socket.gethostname
3. PMI_Rank variable
4. Works on laptop, need to test HPC
5. Works on HPC. Limitation 1 task or keras run per node.
6. PMI_Rank - not available on HPC