message: travis: add gcc-7 build
diff: @@ -14,12 +14,31 @@ matrix:
  - name: "Python 2.7 gcc-8"
  python: 2.7
  env: CC=gcc-8 CXX=g++-8
  + packages:
  + - g++-8
  + - gcc-8
  +
  - name: "Python 3.5 gcc-8"
  python: 3.5
  env: CC=gcc-8 CXX=g++-8
  + packages:
  + - g++-8
  + - gcc-8
  +
  - name: "Python 3.7 gcc-8"
  python: 3.7
  env: CC=gcc-8 CXX=g++-8
  + packages:
  + - g++-8
  + - gcc-8
  +
  + - name: "Python 3.7 gcc-7"
  + python: 3.7
  + env: CC=gcc-7 CXX=g++-7
  + packages:
  + - g++-7
  + - gcc-7
  +
  addons:
  apt:
  