added tests for index methods of ReVIEW::Chapter
added tests for index methods of ReVIEW::Chapter

krororo/review,takahashim/review,kmuto/review,kuad9/review_study,takahashim/review,kmuto/review,masawada/review,suzuki/review,krororo/review,murashitas/review,krororo/review,murashitas/review,orangain/review,orangain/review,suzuki/review,kuad9/review_study,kdmsnr/review,kmuto/review,masawada/review