message: CI tests for Visual Studio 2015 and 2017
diff: platform: x64
  +image:
  + - Visual Studio 2015
  + - Visual Studio 2017
  +
  environment:
  BOOST_ROOT: C:/Libraries/boost_1_60_0
  BOOST_LIBRARYDIR_WIN32: C:/Libraries/boost_1_60_0/lib32-msvc-14.0
  