Refine Travis config, only PHP 7 here

.travis.yml

@@ -8,31 +8,28 @@ notifications:
     on_success: never
     on_failure: change
 
-branches:
-  only:
-    - master
-
 cache:
   directories:
     - $HOME/.composer/cache
 
 matrix:
   include:
+    - php: 7.2
+      env: WP_VERSION=latest
     - php: 7.1
       env: WP_VERSION=latest
     - php: 7.0
       env: WP_VERSION=latest
-    - php: 5.6
-      env: WP_VERSION=4.4
-    - php: 5.6
-      env: WP_VERSION=latest
-    - php: 5.6
+    - php: 7.2
+      env: WP_VERSION=trunk
+    - php: 7.1
       env: WP_VERSION=trunk
-    - php: 5.6
+    - php: 7.0
+      env: WP_VERSION=trunk
+    - php: 7.1
       env: WP_TRAVISCI=phpcs
-    - php: 5.3
-      env: WP_VERSION=latest
-      dist: precise
+  allow_failures:
+    - php: 7.2
 
 before_script:
   - export PATH="$HOME/.composer/vendor/bin:$PATH"