message: Advanced gcc version in travis.yml
diff: @@ -13,9 +13,9 @@ matrix:
  sources:
  - ubuntu-toolchain-r-test
  packages:
  - - g++-7
  + - g++-9
  env:
  - - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
  + - MATRIX_EVAL="CC=gcc-9 && CXX=g++-9"
  # - os: osx
  # osx_image: xcode11.2
  # env:
  