Fix: BucketBatchSampler's lambda in snli example

[mrshu]

• The BucketBatchSampler's sort_key lambda function in examples/snli/train.py used the row variable, which was loaded due to the for loop a few dozens line above. This also meant that the sort_key lambda function did not have too much of an effect, as it always returned the same number.

• The same issue can be seen in case of the dev dataset.

• This commit fixes the situation by making use of the passed index and the loaded train and dev datasets.

[codecov-io]

Codecov Report

Merging #97 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #97   +/-   ##
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  Coverage   94.41%   94.41%           
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  Files          63       63           
  Lines        1594     1594           
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  Hits         1505     1505           
  Misses         89       89

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[codecov-commenter]

Codecov Report

Merging #97 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #97   +/-   ##
=======================================
  Coverage   94.41%   94.41%           
=======================================
  Files          64       64           
  Lines        1611     1611           
=======================================
  Hits         1521     1521           
  Misses         90       90           

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Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update a741b0c...cf9f1ce. Read the comment docs.