[BRANCH-0.4.x] FIX pickle RootLogger

[HyukjinKwon]

This PR backports #160.

[codecov-io]

Codecov Report

Merging #167 into 0.4.x will increase coverage by 0.09%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##            0.4.x     #167      +/-   ##
==========================================
+ Coverage   83.73%   83.82%   +0.09%     
==========================================
  Files           1        1              
  Lines         535      538       +3     
  Branches       97       97              
==========================================
+ Hits          448      451       +3     
  Misses         63       63              
  Partials       24       24

Impacted Files	Coverage Δ
cloudpickle/cloudpickle.py	83.82% <100%> (+0.09%)	⬆️

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[HyukjinKwon]

@rgbkrk BTW, do you want me to release 0.5.3v too?

[rgbkrk]

That would be great.