Downgrading PHPUnit to version 6.0 to support PHP 7.0

Author: tortuetorche

composer.json

@@ -27,7 +27,7 @@
         "laravel/scout": "~4.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~7.0",
+        "phpunit/phpunit": "~6.0",
         "mockery/mockery": "~1.0"
     },
     "autoload": {