[jvm-packages] update rabit, surface new changes to spark, add parity and failure tests (#4966)
* [phase 1] expose sets of rabit configurations to spark layer
* add back mutable import
* disable ring_mincount till https://github.com/dmlc/rabit/pull/106d
* Revert "disable ring_mincount till https://github.com/dmlc/rabit/pull/106d"
This reverts commit 65e95a98e24f5eb53c6ba9ef9b2379524258984d.
* apply latest rabit
* fix build error
* apply https://github.com/dmlc/xgboost/pull/4880
* downgrade cmake in rabit
* point to rabit with DMLC_ROOT fix
* relative path of rabit install prefix
* split rabit parameters to another trait
* misc
* misc
* Delete .classpath
* Delete .classpath
* Delete .classpath
* Update XGBoostClassifier.scala
* Update XGBoostRegressor.scala
* Update GeneralParams.scala
* Update GeneralParams.scala
* Update GeneralParams.scala
* Update GeneralParams.scala
* Delete .classpath
* Update RabitParams.scala
* Update .gitignore
* Update .gitignore
* apply rabitParams to training
* use string as rabit parameter value type
* cleanup
* add rabitEnv check
* point to dmlc/rabit
* per feedback
* update private scope
* misc
* update rabit
* add rabit_timtout, fix failing test.
* split tests
* allow build jvm with rabit mock
* pass mock failures to rabit with test
* add mock error and graceful handle rabit assertion error test
* split mvn test
* remove sign for test
* update rabit
* build jvm_packages with rabit mock
* point back to dmlc/rabit
* per feedback, update scala header
* cleanup pom
* per feedback
* try fix lint
* fix lint
* per feedback, remove bootstrap_cache
* per feedback 2
* try replace dev profile with passing mvn property
* fix build error
* remove mvn property and replace with env setting to build test jar
* per feedback
* revert copyright headlines, point to dmlc/rabit
* revert python lint
* remove multiple failure test case as retry is not enabled in spark
* Update core.py
* Update core.py
* per feedback, style fix
b29b8c2f34