Install CMake using Kitware installer

.travis.yml

@@ -42,13 +42,6 @@ addons:
       - wget
       - r
     update: true
-  apt:
-    sources:
-      - sourceline: 'deb https://apt.kitware.com/ubuntu/ bionic main'
-        key_url: 'https://apt.kitware.com/keys/kitware-archive-latest.asc'
-    packages:
-      - cmake
-    update: true
 
 before_install:
   - source tests/travis/travis_setup_env.sh

tests/travis/setup.sh

@@ -19,3 +19,9 @@ 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
+    cmake --version
+fi