message: memo: small update to pass test suite
diff: "compiler": {
  "c++": "201103",
  "family": "clang",
  - "version": "9.1.0 (clang-902.0.39.2)"
  + "version": "10.0.0 (clang-1000.10.43.1)"
  },
  "copyright": "(C) 2013-2017 Niels Lohmann",
  "name": "JSON for Modern C++",
  