Updated travis php env

vuongxuongminh · vuongxuongminh · commit e6785ccd4d30 · 2019-05-25T00:11:46.000+07:00
diff --git a/.travis.yml b/.travis.yml
@@ -2,6 +2,8 @@ language: php
 
 php:
     - 7.1
+    - 7.2
+    - 7.3
 
 install:
     - composer self-update
