[MRG] 👽 Maintenance for `imblearn.show_versions()`, fix Travis build

[hayesall]

Summary

• Drop get_blas_info() vendored from sklearn
• Fix unit tests to reflect the fix

What does this implement/fix? Explain your changes.

imblearn/utils/_show_versions used several utilities from scikit-learn. BLAS/CBLAS were recently dropped and get_blas_info() was removed.

This patch reflects these changes.

Any other comments?

See scikit-learn#14205

[pep8speaks]

Hello @hayesall! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2019-08-14 16:30:23 UTC

[codecov]

Codecov Report

Merging #591 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #591      +/-   ##
==========================================
- Coverage   98.92%   98.92%   -0.01%     
==========================================
  Files          85       85              
  Lines        5324     5310      -14     
==========================================
- Hits         5267     5253      -14     
  Misses         57       57

Impacted Files	Coverage Δ
imblearn/utils/_show_versions.py	100% <100%> (ø)	⬆️
imblearn/utils/tests/test_show_versions.py	100% <100%> (ø)	⬆️

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[hayesall]

Build is still failing on Travis with:

ReadError('file could not be opened successfully')

edit:

It looks like the error is stemming from install.sh when creating a new conda environment, but it will take me a bit longer to debug it.

edit2:

It looks like updating conda resolves this error:

- conda install --yes conda=4.6
+ conda config --set always_yes yes --set changeps1 no
+ conda install conda=4.6
+ conda update -q conda

I also added a few of the recommendations from the conda + Travis guide, such as printing debug information and setting default values.

[hayesall]

@glemaitre, @chkoar Errors with Travis-CI should be resolved now. This should also fix the build failure in #592

[chkoar]

Thanks