Update .travis.yml

KanDisheng · KanDisheng · commit 88a723ca1edc · 2018-01-30T15:08:50.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -9,6 +9,7 @@ php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
 before_script:
   - composer install
 script:
