update cmake version

.travis.yml

@@ -4,10 +4,6 @@ dist: bionic
 addons:
   apt:
     update: true
-before_install:
-  - wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh
-  - sudo sh cmake.sh --skip-license --exclude-subdir --prefix=/usr/local
-  - export PATH="$PATH:/usr/local"
 install:
   - source $TRAVIS_BUILD_DIR/ci/travis/install_dependency.sh
 script:

core/CMakeLists.txt

@@ -18,7 +18,7 @@
 #-------------------------------------------------------------------------------
 
 
-cmake_minimum_required(VERSION 3.14)
+cmake_minimum_required(VERSION 3.12)
 message(STATUS "Building using CMake version: ${CMAKE_VERSION}")
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
@@ -273,4 +273,4 @@ if (${CLANG_TIDY_FOUND})
             --source_dir
             ${CMAKE_CURRENT_SOURCE_DIR}/src
             ${MILVUS_LINT_QUIET})
-endif ()
+endif ()
\ No newline at end of file

core/src/index/CMakeLists.txt

@@ -18,7 +18,7 @@
 #-------------------------------------------------------------------------------
 
 
-cmake_minimum_required(VERSION 3.14)
+cmake_minimum_required(VERSION 3.12)
 message(STATUS "------------------------------KNOWHERE-----------------------------------")
 message(STATUS "Building using CMake version: ${CMAKE_VERSION}")