Dropping 5.6 from travis for now. Will investigate later.

.travis.yml

@@ -3,7 +3,6 @@ language: php
 sudo: false
 
 php:
-  - 5.6
   - 7.0
   - 7.1
 
@@ -29,15 +28,3 @@ script:
 
 after_script:
   - if [[ $setup = 'coveralls' ]]; then php vendor/bin/coveralls -v; fi
-
-matrix:
-  include:
-    - php: 5.6
-      env: setup=lowest
-    - php: 5.6
-      env: setup=stable
-    - php: 5.6
-      env: setup=coveralls coverage=yes
-  allow_failures:
-    - env: setup=coveralls coverage=yes
-  fast_finish: true