message: travis: rm redundant packages
diff: @@ -17,7 +17,6 @@ matrix:
  addons:
  apt:
  packages:
  - - g++-8
  - gcc-8
  - name: "Python 3.5 gcc-8"
  @@ -26,7 +25,6 @@ matrix:
  addons:
  apt:
  packages:
  - - g++-8
  - gcc-8
  - name: "Python 3.7 gcc-8"
  @@ -35,7 +33,6 @@ matrix:
  addons:
  apt:
  packages:
  - - g++-8
  - gcc-8
  - name: "Python 3.7 gcc-7"
  @@ -44,7 +41,6 @@ matrix:
  addons:
  apt:
  packages:
  - - g++-7
  - gcc-7
  - ninja-build
  @@ -57,8 +53,6 @@ addons:
  packages:
  - build-essential
  - cython
  - - g++-8
  - - gcc-8
  # command to install dependencies
  