Merge pull request #151 from wp-cli/test-php-7-2

Add Travis job for testing PHP 7.2

Author: gitlost

.travis.yml

@@ -24,6 +24,8 @@ env:
 
 matrix:
   include:
+    - php: 7.2
+      env: WP_VERSION=nightly
     - php: 7.1
       env: WP_VERSION=latest
     - php: 7.0