Add some OIDC flow tests.

Enable testing for gregui, add a django config for testing.

frontend/public/locales/en/common.json

 {
-  "test": "This is a test",
-  "nested": {
-    "test": "This is a nested value"
-  },
   "language": {
     "change": "Change language to {{lang}}"
   },
@@ -75,5 +71,7 @@
     "guestRole": "Guest role",
     "guestPeriod":"Period",
     "guestDepartment": "Department"
-  }
+  },
+  "yourGuests": "Your guests",
+  "registerNewGuest": "Register new guest"
 }