PHP-5.3 is not available on trusty, so explicitly specify precise for 5.3

Author: erayd

.travis.yml

@@ -10,6 +10,7 @@ matrix:
   fast_finish: true
   include:
     - php: 5.3
+      dist: precise
     - php: 5.4
     - php: 5.5
     - php: 5.6