Fix : Semi-Supervised Learning fails

[kweonwooj]

Problem

Current implementation fails to reproduce semi-supervised method you mention in solution.pdf.
This is due to data.py #L103~104 where all the test data is assigned a label of len(self.label_words_dict), which is unknown.
There is no execution error, but kaggle submission results in ~0.15.

Solution

• return both list of data and list of label in get_sub_list() so that correct labels are fed for semi-supervised setting
• this fix results in public/private leaderboard score ~0.85 which is decent, but does not improve overall ensemble score as mentioned in solution.pdf