Update merge-person script to handle contraints and roles. Commit ready for merge.

- Legacy-Id: 9715

ietf/bin/merge-person-records

@@ -56,6 +56,16 @@ for subevent in source.submissionevent_set.all():
     subevent.by = target
     subevent.save()
 
+# merge Constraints
+for constraint in source.constraint_set.all():
+    constraint.person = target
+    constraint.save()
+
+# merge Roles
+for role in source.role_set.all():
+    role.person = target
+    role.save()
+
 # check for any remaining relationships and delete if none
 objs = [source]
 opts = Person._meta