Update GOVERNANCE.md (#6358)

* Update GOVERNANCE.md

Remove per request #6334 (comment)

* Add to alumni

* Fix to make consistent

Author: canyon289

GOVERNANCE.md

@@ -175,7 +175,6 @@ Contributors don't need to be part of any dedicated team.
 * Ben Mares
 * Benjamin Vincent (docs - PyMC Labs)
 * Bill Engels (dev)
-* Brandon T. Willard (dev)
 * Chris Fonnesbeck (dev, docs)
 * Christian Luhmann (community)
 * Colin Carroll (dev)
@@ -820,6 +819,7 @@ extra benefits but those will be related to the conference, not the Project.
 
 * Agustina Arroyuelo (GSoC 2018)
 * Anand Patil
+* Brandon T. Willard
 * David Huard
 * Demetri Pananos (GSoC 2019)
 * John Salvatier