Add google test for a column sampling, restore metainfo tests#3637

Merged

RAMitchell merged 3 commits intodmlc:masterfrom RAMitchell:update-gtests

Aug 28, 2018

+102-3

Commits on Aug 27, 2018

Add google test for a column sampling, restore metainfo tests
RAMitchell
committed

Commits on Aug 28, 2018