optionally override hostname used for default remote rundir

[bernstei]

When jobs are being submitted from machines with different names, e.g. multiple login nodes of an hpc, having the submitting hostname be part of the remote rundir is bad, because it means that rerunning the script between job submission and result gathering fails if those two steps are done from different hostnames.

Possible fixes

1. remote hostname from remote rundir entirely
2. make a config option to remove hostname part of remote rundir
3. make a config option to set the effective hostname

[bernstei]

@ThomasWarford do you have an opinion?

[bernstei]

I'm leaning toward 3, perhaps a field called "remote_rundir_submit_hostname" in the top level of the config.json file, outside of "systems", which will override environ["HOSTNAME"] in the remote rundir name if provided.

[ThomasWarford]

I think option 3 sounds best too

[bernstei]

Do you want to test out the branch in #43 before I merge?

[ThomasWarford]

Sure, thanks for the quick response. It might be a few days before I test though because I have many jobs to run and want to get them finished before changing anything

[ThomasWarford]

I submitted 8 calculations on one node and gathered them on another. Seems good to me!