Periodic stable branch testing

[Kevin Traynor]

Hello LTS maintainers and Lincoln,

Lincoln let me know that UNH can do periodic testing on stable branches.

When I looked at the public dashboard [0] i'm confused with what is 
running as there doesn't seem to have been runs for a long time and 
there are many failures.

So I'm wondering if/how they are being used by LTS maintainers and what 
exactly they are testing?

thanks,
Kevin.

[0]
20.11 : 
https://dpdkdashboard.iol.unh.edu/results/dashboard/periodic_testing/?branch_id=13&page=0

19.11 : 
https://dpdkdashboard.iol.unh.edu/results/dashboard/periodic_testing/?branch_id=14&page=0