message: Patch nlohmann_json to allow cmake 3.6
diff: -cmake_minimum_required(VERSION 3.8)
  +cmake_minimum_required(VERSION 3.6)
  ##
  ## PROJECT
  @@ -46,7 +46,15 @@ endif()
  ##
  add_library(${NLOHMANN_JSON_TARGET_NAME} INTERFACE)
  add_library(${PROJECT_NAME}::${NLOHMANN_JSON_TARGET_NAME} ALIAS ${NLOHMANN_JSON_TARGET_NAME})
  +
  +# Use meta-compile features if available, otherwise use specific language
  +# features
  +if(cxx_std_11 IN_LIST CMAKE_CXX_COMPILE_FEATURES)
  target_compile_features(${NLOHMANN_JSON_TARGET_NAME} INTERFACE cxx_std_11)
  +else()
  + target_compile_features(${NLOHMANN_JSON_TARGET_NAME}
  + INTERFACE cxx_auto_type cxx_constexpr)
  +endif()
  target_include_directories(
  ${NLOHMANN_JSON_TARGET_NAME}
  