message: Testing out gcc 6 and 7, 5 is not compatible it seems
diff: @@ -7,17 +7,26 @@ notifications:
  matrix:
  include:
  - # GCC 4.9
  + # GCC 6
  - os: linux
  addons:
  apt:
  sources:
  - ubuntu-toolchain-r-test
  packages:
  - - g++-4.9
  + - g++-6
  env:
  - - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
  -
  + - MATRIX_EVAL="CC=gcc6 && CXX=g++-6"
  + # GCC 7
  + - os: linux
  + addons:
  + apt:
  + sources:
  + - ubuntu-toolchain-r-test
  + packages:
  + - g++-7
  + env:
  + - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
  # Clang 4.0
  - os: linux
  addons:
  @@ -28,7 +37,6 @@ matrix:
  - clang-4.0
  env:
  - MATRIX_EVAL="CC=clang-4.0 && CXX=clang++-4.0"
  -
  # Clang 4.9
  - os: osx
  osx_image: xcode8
  