Add migration for creation of Fairphone staff group

Issue: HIC-247
Change-Id: I44b3db32e3646fae8d7d9ff37dc203c6c2c65756
diff --git a/crashreport_stats/tests/utils.py b/crashreport_stats/tests/utils.py
index 9157a63..279320b 100644
--- a/crashreport_stats/tests/utils.py
+++ b/crashreport_stats/tests/utils.py
@@ -336,8 +336,7 @@
         cls.admin = APIClient()
         cls.admin.force_login(admin_user)
 
-        fp_staff_group = Group(name=FP_STAFF_GROUP_NAME)
-        fp_staff_group.save()
+        fp_staff_group = Group.objects.get(name=FP_STAFF_GROUP_NAME)
         fp_staff_user = User.objects.create_user(
             "fp_staff", "somebody@fairphone.com", "thepassword"
         )