Fix GH-248

[sharthZ23]

I think, this will fix #248
Can't run tests, because in my version of xgboost xgb.booster() must be replaced by xgb.get_booster()

[codecov-io]

Codecov Report

Merging #249 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #249      +/-   ##
==========================================
+ Coverage   97.22%   97.22%   +<.01%     
==========================================
  Files          44       44              
  Lines        2813     2814       +1     
  Branches      535      535              
==========================================
+ Hits         2735     2736       +1     
  Misses         41       41              
  Partials       37       37

Impacted Files	Coverage Δ
eli5/xgboost.py	99.38% <100%> (ø)	⬆️

[gabrielelanaro]

Any chance this pull request will be merged? This is quite an important bug

[lopuhin]

Sorry for slow feedback @sharthZ and @gabrielelanaro , I think there are two items preventing the merge:

• it would be nice to add a test to this PR that checks that this does fix the issue with boolean attributes
• unrelated to this PR: unfortunately, eli5 does not work with xgboost 0.7 at the moment which causes tests to fail, so in order to run them we need to either pin xgboost to <0.7 temporary in tests, or to fix the issues with xgboost 0.7