Redefine user roles with their role in a study group

spec/factories/external_user.rb

@@ -7,5 +7,9 @@ FactoryBot.define do
     external_id { SecureRandom.uuid }
     generated_user_name
     singleton_external_user
+    member_of_study_group
+    transient do
+      teacher_in_study_group { false }
+    end
   end
 end