Icu 5229 credential model (#1197)

* feat: 🎸 Create Credential Model in API

✅ Closes: ICU-5229

Co-authored-by: Cameron Perera <cameron.perera@hashicorp.com>

addons/api/tests/unit/models/credential-test.js

@@ -0,0 +1,13 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Model | credential', function(hooks) {
+  setupTest(hooks);
+
+  // Replace this with your real tests.
+  test('it exists', function(assert) {
+    let store = this.owner.lookup('service:store');
+    let model = store.createRecord('credential', {});
+    assert.ok(model);
+  });
+});