parallelize test suite

[Rollins, Jameson]

On Sat, May 04 2019, "Rollins, Jameson" <jrollins at caltech.edu> wrote:
> This is a simple patch series that will run the entire test suite in
> parallel if either the moreutils or GNU parallel utility is
> available.  On my 8-core machine the full test suite will now run in
> under 20 seconds, which is a pretty huge improvement.

Sorry I actually meant 12 seconds, not 20.