Merge pull request #979 from dunglas/fix_travis

[WIP] Fix Travis setup

Author: dunglas

.travis.yml

@@ -10,7 +10,7 @@ cache:
 matrix:
   include:
     - php: '7.0'
-    - php: '7.1'
+    - php: '7.1.0' # Prevent phpdbg's segfaults
       env: coverage=1 lint=1
     - php: '7.1'
       env: deps='low'