.travis.yml: experiment with Python versions #5

Author: davidmalcolm

.travis.yml

@@ -1,77 +1,63 @@
-matrix:
-  include:
-    - os: linux
+os: linux
+
+env:
+  - MATRIX_EVAL="CC=gcc-4.8 && CXX=g++-4.8"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-4.8 gcc-4.8-plugin-dev
-      env:
-         - MATRIX_EVAL="CC=gcc-4.8 && CXX=g++-4.8"
 
-    # works on Precise and Trusty
-    - os: linux
+  - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-4.9 gcc-4.9-plugin-dev
-      env:
-         - MATRIX_EVAL="CC=gcc-4.9 && CXX=g++-4.9"
 
-    # works on Precise and Trusty
-    - os: linux
+  - MATRIX_EVAL="CC=gcc-5 && CXX=g++-5"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-5 gcc-5-plugin-dev
-      env:
-         - MATRIX_EVAL="CC=gcc-5 && CXX=g++-5"
 
-    # works on Precise and Trusty
-    - os: linux
+  - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-6 gcc-6-plugin-dev
       env:
-        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"
 
-    # works on Precise and Trusty
-    - os: linux
+  - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-7 gcc-7-plugin-dev
-      env:
-        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
 
-    - os: linux
+  - MATRIX_EVAL="CC=gcc-8 && CXX=g++-8"
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-8 gcc-8-plugin-dev
       env:
-        - MATRIX_EVAL="CC=gcc-8 && CXX=g++-8"
 
-matrix:
-  include:
-    - python: "2.7"
-    - python: "3.3"
-    - python: "3.4"
-    - python: "3.5"
-    - python: "3.6"
-    - python: "3.7-dev"  # 3.7 development branch
+python:
+  - "2.7"
+  - "3.3"
+  - "3.4"
+  - "3.5"
+  - "3.6"
+  - "3.7-dev"  # 3.7 development branch
 
 language: c
 compiler: