[MRG] Tests with types/device on sliced/bregman/gromov functions

[ncassereau]

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Motivation and context / Related issue

Unit tests for GPUs

How has this been tested (if it applies)

Checklist

• The documentation is up-to-date with the changes I made.
• I have read the CONTRIBUTING document.
• All tests passed, and additional code has been covered with new tests.

[codecov]

Codecov Report

Merging #303 (f31c15d) into master (0e431c2) will increase coverage by 0.01%.
The diff coverage is 91.66%.

❗ Current head f31c15d differs from pull request most recent head f0beebf. Consider uploading reports for the commit f0beebf to get more accurate results

@@            Coverage Diff             @@
##           master     #303      +/-   ##
==========================================
+ Coverage   93.39%   93.40%   +0.01%     
==========================================
  Files          21       21              
  Lines        4860     4886      +26     
==========================================
+ Hits         4539     4564      +25     
- Misses        321      322       +1