message: Mostly testing on Ubuntu 18.04 now
diff: @@ -27,7 +27,7 @@ Build requirements
  ------------------
  - C++11 compliant compiler
  - (tested with g++-5.4.0 on Ubuntu 16.04 x86_64,
  + (tested with g++-7.4.0 on Ubuntu 18.04 x86_64,
  tested with clang-900.0.39.2 on Mac OS X 10.13,
  tested with Microsoft Visual Studio 2015 VC14 for x64)
  