Add system info to report outputs

[tsalo]

Summary

From today's dev call, we want to collect and save system/environment info among out report outputs, in order to improve reproducibility.

Additional Detail

I thought we could take something from rapidtide for this, but it turns out they just output the parameters used in the run (which is still useful information that we could output) in a json. I know there are some packages that output system information, but for some reason I can't find any right now. Will need to revisit later.

Next Steps

1. Find a Python library that outputs system information and adopt their approach.
2. Write out a file with system info at the beginning of each workflow run.

[jbteves]

For a start, here's platform