Merge pull request #69 from jcfr/require-cmake-greater-or-equal-38

cmake: Require version >= 3.8 to ensure try_compile consider CMAKE_(C|CXX)_STANDARD

CMakeLists.txt

@@ -6,7 +6,7 @@
 # The full license is in the file LICENSE, distributed with this software. #
 ############################################################################
 
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.8)
 project(xeus)
 
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake;${CMAKE_MODULE_PATH}")