binary mnist dm fix

[annikabrundyn]

Fixes dataset not found error mentioned in issue #353

Reran the notebook that produced the error and it's now working:

https://colab.research.google.com/drive/1PHwAm48SNojrYbQWPeihmsbWuH-h6KU8#scrollTo=Kh5dXKO4Tr8Y

[codecov]

Codecov Report

Merging #377 (0d71c09) into master (77ff983) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #377      +/-   ##
==========================================
+ Coverage   81.18%   81.22%   +0.03%     
==========================================
  Files         100      100              
  Lines        5715     5714       -1     
==========================================
+ Hits         4640     4641       +1     
+ Misses       1075     1073       -2     

Flag	Coverage Δ
cpu	24.27% <100.00%> (-0.02%)	⬇️
pytest	24.27% <100.00%> (-0.02%)	⬇️
unittests	80.50% <100.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...lts/models/self_supervised/simclr/simclr_module.py	71.49% <ø> (-0.14%)	⬇️
.../models/self_supervised/simclr/simclr_finetuner.py	100.00% <100.00%> (ø)
pl_bolts/datasets/base_dataset.py	100.00% <0.00%> (+4.54%)	⬆️

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[akihironitta]

LGTM. Thank you for the swift action :]

[Borda]

@akihironitta it seems that the Dataset caching does not work as expected or we shall not download it if it already exists...
just most of the tests failed because of

UNEXPECTED EXCEPTION: RuntimeError('Failed download from https://www.cs.toronto.edu/~kriz/cifar-10-python.tar.gz')

[akihironitta]

@Borda I'll dig into it :]