Remove dmlc logger

[hcho3]

Extracted from #285. Re-implement logging functionalities such as CHECK and LOG, so that we no longer depend on the header dmlc/logging.h.

[codecov]

Codecov Report

Merging #287 (7bf2625) into mainline (e99ca01) will increase coverage by 0.06%.
The diff coverage is 100.00%.

@@              Coverage Diff               @@
##             mainline     #287      +/-   ##
==============================================
+ Coverage       85.03%   85.10%   +0.06%     
  Complexity         46       46              
==============================================
  Files             106      106              
  Lines            7978     8014      +36     
  Branches           50       50              
==============================================
+ Hits             6784     6820      +36     
  Misses           1169     1169              
  Partials           25       25              

Impacted Files	Coverage Δ
include/treelite/c_api_error.h	100.00% <ø> (ø)
include/treelite/frontend.h	90.00% <ø> (ø)
include/treelite/predictor.h	92.30% <ø> (ø)
src/annotator.cc	91.47% <ø> (ø)
src/c_api/c_api.cc	97.09% <ø> (ø)
src/compiler/ast/dump.cc	0.00% <ø> (ø)
src/compiler/ast/fold_code.cc	86.79% <ø> (ø)
src/compiler/ast/quantize.cc	98.11% <ø> (ø)
src/compiler/ast/split.cc	97.72% <ø> (ø)
src/compiler/common/code_folding_util.h	96.80% <ø> (ø)
... and 18 more

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[hcho3]

@trivialfis Thank you so much for reviewing the 7 pull requests! I was worried about the size of the changes required to remove dmlc, but thanks to your review, I can merge it with a peace of mind.