Rename unit test.

Author: mfahadahmed

packages/optimizely-sdk/lib/core/decision_service/index.tests.js

@@ -890,7 +890,7 @@ describe('lib/core/decision_service', function() {
             sinon.assert.calledWithExactly(mockLogger.log, LOG_LEVEL.DEBUG, 'DECISION_SERVICE: User user1 is not in any experiment on the feature feature_with_group.');
           });
 
-          it('bucketed group experiment does not exist in the feature', function() {
+          it('returns null decision for group experiment not referenced by the feature', function() {
             var noTrafficExpFeature = configObj.featureKeyMap.feature_exp_no_traffic;
             var decision = decisionServiceInstance.getVariationForFeature(noTrafficExpFeature, 'user1');
             var expectedDecision = {