Update PSC.md to add Julien Radoux as a PSC member

3 jobs for add-jradoux-to-psc in 6 minutes and 5 seconds (queued for 1 second)
Status Job ID Name Coverage
  Precheck
passed #4868
fast-build

00:06:05

failed #4857
fast-build

01:43:56

 
  External
passed cdash:ubuntu-18.04-fast