Update test for review-action model to reflect target relationship change

Author: Uditi Mehta

tests/unit/models/review-action-test.ts

@@ -27,7 +27,7 @@ module('Unit | Model | review-action', hooks => {
         const relationship = get(model, 'relationshipsByName').get('target');
 
         assert.equal(relationship.key, 'target');
-        assert.equal(relationship.type, 'registration');
+        assert.equal(relationship.type, 'abstract-node');
         assert.equal(relationship.kind, 'belongsTo');
     });