add phpunit test to composer

Author: JBlond

README.md

@@ -94,6 +94,7 @@ see [License](LICENSE)
 ## tests
 
 ```BASH
+composer run-script phpunit
 composer run-script php_src
 composer run-script php_test
 ```

composer.json

@@ -31,6 +31,7 @@
         }
     },
     "scripts": {
+        "phpunit": "phpunit ./tests/",
         "php_src": "phpcs --standard=phpcs.xml -s -p --colors ./lib/",
         "php_test": "phpcs --standard=phpcs.xml -s -p --colors ./tests/"
     }