Merge pull request #144 from webimpress/phpunit-7

 Allow PHPUnit 7

Author: weierophinney

composer.json

@@ -29,7 +29,7 @@
         "zendframework/zend-validator": "^2.10.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.4.1 || ^5.7.15",
+        "phpunit/phpunit": "^5.7.27 || ^6.5.8 || ^7.1.3",
         "zendframework/zend-coding-standard": "~1.0.0",
         "zendframework/zend-config": "^3.1 || ^2.6"
     },