Refactor Test#createFeatureList() and Test#group()
Add `Object.assign()`, and use it
Refine even more main.js
Add Test#getFeatureTest(), and use it
Add Test#getScoreData(), and use it
Refine Test#createFeatureList()
Refine Test#group()
Rename Test#group() to Test#createFeatureTitle()
Refine Test#getScoreData() and Test#getFeatureTest()
Rename Test#getFeatureTest() to Test#getFeatureTestList()
Refine Test#getTestResults()

* Refine more Test#getScoreData()
Add Test#createFeatureTest(), and use it

* Refine even more Test#getScoreData()
Refine more Test#createFeatureTitle() and Test#createFeatureList()
Add Array#remove(), and use it
Update `Test`'s method order
Refine Test#passClass()