update travis

Author: Korben Dallas

.travis.yml

@@ -3,10 +3,11 @@ language: php
 php:
   - 7.2
   - 7.3
+  - 8.0
 
 before_script:
   - composer install --prefer-source --no-interaction
   - composer dump-autoload
 
 script:
-  - vendor/bin/phpunit
+  - vendor/bin/phpunit