Containerized UMN

I have been using singularity on the zebras, scorpions, and an interactive node here at UMN for some time now and I think we have reached a stable point of this repository. I may need to make a subsequent release in the coming days to mark any updates to the batch submission system if we find bugs while making samples, but that system has been using singularity for the longest time, so I am hopeful.

Major Changes

• Allow use of /export/scratch/users/$USER/ldmx to be the ldmx base directory. This is helpful on interactive nodes so that the user doesn't have to connect across the intranet when building/running ldmx-sw. This is by no means required and the local directory (/local/cms/user/$USER/ldmx) is still the default.
• User can define the program to be run in the batch machinery. The two that have been tested are fire and python3.
• Removal of old "bare-metal" environment machinery.

Bare Metal Building

Bare Metal Build Release

I've just heard from CSE-IT that singularity is now installed on all the scorpions. This means I can start transitioning our workflows to using the standard container instead of having to piece together the dependencies ourselves. I am making this release to mark the most recent/stable version of ldmx-sw @ UMN that doesn't use the container.

As of today, singularity is not installed on the interactive nodes (the zebras), so the workflows will first be focused on running batch jobs via the scorpion cluster (and assume the work that is not using the batch system is being done elsewhere).