Remove six dependency

[pmeier]

Closes #2015

[pmeier]

@fmassa I did not include it in this PR, but do you want me to remove

vision/torchvision/datasets/voc.py

Lines 7 to 10 in 3c254fb

	if sys.version_info[0] == 2:
	import xml.etree.cElementTree as ET
	else:
	import xml.etree.ElementTree as ET

and the like in a follow up PR?

[fmassa]

Thanks a lot for the PR @pmeier !

I have a comment about str and bytes, let me know what you think. Apart from that, the PR looks good to go

[fmassa]

I did not include it in this PR, but do you want me to remove

yes, please, if you could remove the cElementTree in a follow-up PR it would be great!

[codecov-io]

Codecov Report

Merging #2017 into master will increase coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master   #2017      +/-   ##
=========================================
+ Coverage    0.48%   0.48%   +<.01%     
=========================================
  Files          92      92              
  Lines        7449    7447       -2     
  Branches     1135    1135              
=========================================
  Hits           36      36              
+ Misses       7400    7398       -2     
  Partials       13      13

Impacted Files	Coverage Δ
torchvision/datasets/sbu.py	0% <ø> (ø)	⬆️
torchvision/datasets/flickr.py	0% <0%> (ø)	⬆️
torchvision/datasets/mnist.py	0% <0%> (ø)	⬆️
torchvision/datasets/lsun.py	0% <0%> (ø)	⬆️
torchvision/datasets/utils.py	0% <0%> (ø)	⬆️
torchvision/transforms/transforms.py	0% <0%> (ø)	⬆️
torchvision/datasets/vision.py	0% <0%> (ø)	⬆️

---

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 3c254fb...f6c6dbc. Read the comment docs.

[fmassa]

Thanks a lot @pmeier!