setup.py: Allow use with docutils >=0.16 (fixes #1942)

[moseb]

For #1942

[codecov-io]

Codecov Report

Merging #1944 into develop will increase coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #1944      +/-   ##
===========================================
+ Coverage    92.73%   92.76%   +0.02%     
===========================================
  Files           53       53              
  Lines        10293    10293              
===========================================
+ Hits          9545     9548       +3     
+ Misses         748      745       -3

Impacted Files	Coverage Δ
botocore/credentials.py	98.87% <0%> (+0.33%)	⬆️

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[moseb]

Anyone?

[prometheanfire]

ping? needs rebase

[yan12125]

Hi @moseb are you still working on this? If not I can open another pull request with rebased patch.

[yan12125]

I created a rebased PR at #2011.

[nateprewitt]

This issue should now be resolved in Botocore 1.18.0.