Fixed 'preview' test case and 'preview' test case move on preview
directory
Merge pull request #39 from yoonhyung/master

[BUGFIX] WTC-2255 / WTC -2260 TC 수정
Merge pull request #40 from gseok/master

Fixed 'preview' test case and 'preview' test case move on preview
[TASK] Common TC 수정(Tester Helper API로 변경)
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