message: Clarified CMake version note
diff: cmake_minimum_required(VERSION 3.8.2)
  project(eos)
  if(MSVC)
  - cmake_minimum_required(VERSION 3.9.20170812-g71ee6) # needed for CMAKE_CXX_STANDARD 17
  + cmake_minimum_required(VERSION 3.9.20170812-g71ee6) # needed for CMAKE_CXX_STANDARD 17 on VS2017.3
  endif()
  set(eos_VERSION_MAJOR 0)
  set(eos_VERSION_MINOR 12)
  