Update .travis.yml

KanDisheng · KanDisheng · commit 1ce1177f0d88 · 2018-01-30T15:09:35.000+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:
