✅ Closes: ICU-5916
* test: 💍 Add acceptance test for updating an spk credential ✅ Closes: ICU-5652
* test: 💍 Add credentials CRUDL tests * fix: 🐛 Deleted empty files * test: 💍 Add missing tests for credentials * test: 💍 Revise tests in read-test.js ✅ Closes: ICU-5330