message: Add xcode9.3 to travis and try to include it in allow_failures
diff: @@ -33,6 +33,10 @@ matrix:
  env: C_COMPILER=clang CXX_COMPILER=clang++ GENERATOR_NAME="Xcode"
  osx_image: xcode9.2
  + - os: osx
  + env: C_COMPILER=clang CXX_COMPILER=clang++ GENERATOR_NAME="Xcode"
  + osx_image: xcode9.3
  +
  allow_failures:
  # These are additional combinations that we test but allow to fail, as they're either older compilers (g++-5) or
  # uncommon combinations that would need some workarounds or updates to work.
  @@ -40,6 +44,8 @@ matrix:
  - env: C_COMPILER=gcc-8 CXX_COMPILER=g++-8 GENERATOR_NAME="Unix Makefiles"
  - env: C_COMPILER=clang-5.0 CXX_COMPILER=clang++-5.0 GENERATOR_NAME="Unix Makefiles"
  - env: C_COMPILER=clang-6.0 CXX_COMPILER=clang++-6.0 GENERATOR_NAME="Unix Makefiles"
  + - env: C_COMPILER=clang CXX_COMPILER=clang++ GENERATOR_NAME="Xcode"
  + osx_image: xcode9.3
  install:
  - |
  