Ensure that configured dmlc/build_config.h is picked up by Rabit and XGBoost (#5514)

* Ensure that configured header (build_config.h) from dmlc-core is picked up by Rabit and XGBoost

* Check which Rabit target is being used

* Use CMake 3.13 in all Jenkins tests

* Upgrade CMake in Travis CI

* Install CMake using Kitware installer

* Remove existing CMake (3.12.4)

tests/travis/setup.sh

@@ -19,3 +19,10 @@ fi
 if [ ${TASK} == "cmake_test" ] && [ ${TRAVIS_OS_NAME} == "osx" ]; then
     sudo softwareupdate -i "Command Line Tools (macOS High Sierra version 10.13) for Xcode-9.3"
 fi
+
+if [ ${TASK} == "python_sdist_test" ] && [ ${TRAVIS_OS_NAME} == "linux" ]; then
+    wget https://github.com/Kitware/CMake/releases/download/v3.17.1/cmake-3.17.1-Linux-x86_64.sh
+    sudo bash cmake-3.17.1-Linux-x86_64.sh --prefix=/usr/local --skip-license
+    sudo rm -rf /usr/local/cmake-3.12.4  # Remove existing CMake
+    cmake --version
+fi