fixed travis timezone config

.travis.yml

@@ -11,6 +11,7 @@ services:
   - elasticsearch
 
 before_script:
+  - echo 'date.timezone = "UTC"' >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
   - composer self-update && composer --version
   - composer require satooshi/php-coveralls 0.6.* --dev --prefer-dist
   - mysql -e 'CREATE DATABASE yiitest;';