Merge pull request #42 from pxgamer/feature/php7.3-travis

Add Travis support for PHP 7.3

.travis.yml

@@ -3,16 +3,13 @@ language: php
 
 php:
 - 7.2
+- 7.3
 - nightly
 
 matrix:
   allow_failures:
   - php: nightly
 
-# This triggers builds to run on the new TravisCI infrastructure.
-# See: https://docs.travis-ci.com/user/reference/trusty#Container-based-with-sudo%3A-false
-sudo: false
-
 ## Cache composer
 cache:
   directories: