Update membership list

Author: stmontgomery

_data/testing-workgroup/members.yml

@@ -1,7 +1,27 @@
-- name: Member 1
-  handle: member1
+- name: Brandon Williams
+  handle: mbrandonw
   affiliation:
 
-- name: Member 2
-  handle: member2
+- name: Brian Croom
+  handle: briancroom
   affiliation:
+
+- name: Jonathan Grynspan
+  handle: grynspan
+  affiliation:
+
+- name: Maarten Engels
+  handle: maartene
+  affiliation:
+
+- name: Paul LeMarquand
+  handle: plemarquand
+  affiliation:
+
+- name: Rachel Brindle
+  handle: younata
+  affiliation:
+
+- name: Stuart Montgomery
+  handle: smontgomery
+  affiliation: Chair