Fix minimum version in test/headers/CMakeLists.txt

Author: pdimov

test/headers/CMakeLists.txt

@@ -2,7 +2,7 @@
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
 
-cmake_minimum_required(VERSION 3.2)
+cmake_minimum_required(VERSION 3.5)
 
 if(POLICY CMP0074)
   cmake_policy(SET CMP0074 NEW)