Revert "update cmake to v3.14 for travis (#20042)" (#20054)

This reverts commit 19ce984.

Author: minggo

tools/travis-scripts/before-install.sh

@@ -50,29 +50,6 @@ function install_latest_python()
     python -V
 }
 
-# update cmake version to 3.14
-function update_cmake_to_314()
-{
-
-    if [ "$TRAVIS_OS_NAME" == "osx" ]; then
-        curl https://cmake.org/files/v3.14/cmake-3.14.0-Darwin-x86_64.tar.gz -O
-        tar -xzf cmake-3.14.0-Darwin-x86_64.tar.gz
-        sudo mv cmake-3.14.0-Darwin-x86_64/CMake.app /Applications
-    else
-        # linux system
-        # build with source code
-        echo "downloading cmake 3.14.0"
-        curl https://cmake.org/files/v3.14/cmake-3.14.0.tar.gz > ./cmake-3.14.0.tar.gz
-        echo "extract cmake 3.14.0"
-        tar -xzf cmake-3.14.0.tar.gz > /dev/null
-        cd cmake-3.14.0
-        echo "build and install cmake 3.14.0"
-        cmake . > /dev/null
-        make > /dev/null
-        sudo make install
-    fi
-}
-
 # set up environment according os and target
 function install_environement_for_pull_request()
 {
@@ -92,8 +69,6 @@ function install_environement_for_pull_request()
         install_python_module_for_osx
     fi
 
-    update_cmake_to_314
-
     # use NDK's clang to generate binding codes
     install_android_ndk
     download_deps