[DO NOT MERGE] Add OSX CI

[fmassa]

No description provided.

[codecov-io]

Codecov Report

Merging #1290 into master will decrease coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1290      +/-   ##
==========================================
- Coverage    65.6%   65.55%   -0.06%     
==========================================
  Files          74       74              
  Lines        5786     5786              
  Branches      884      884              
==========================================
- Hits         3796     3793       -3     
- Misses       1725     1726       +1     
- Partials      265      267       +2

Impacted Files	Coverage Δ
torchvision/transforms/transforms.py	80.55% <0%> (-0.4%)	⬇️
torchvision/transforms/functional.py	71.09% <0%> (-0.29%)	⬇️

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[fmassa]

Subsumed by #1298