Update CMake version

Author: frabert

.travis.yml

@@ -68,7 +68,7 @@ matrix:
         - export ANDROID_NDK_HOME=$ANDROID_HOME/ndk-bundle
       install:
         - sudo apt-get purge cmake
-        - curl -o cmake_install.sh https://cmake.org/files/v3.11/cmake-3.11.1-Linux-x86_64.sh
+        - curl -o cmake_install.sh https://cmake.org/files/v3.12/cmake-3.12.2-Linux-x86_64.sh
         - sudo chmod +x ./cmake_install.sh
         - sudo ./cmake_install.sh --prefix=/opt/ --exclude-subdir --skip-license
         - export PATH=/opt/bin/:$PATH