composer config updated for test suite

Author: mkorkmaz

composer.json

@@ -19,8 +19,8 @@
     "selami/stdlib": "^1.8"
   },
   "require-dev": {
-    "phpunit/phpunit": "^7.0",
-    "php-coveralls/php-coveralls": "~1.0",
+    "phpunit/phpunit": "^7.5",
+    "php-coveralls/php-coveralls": "^2.1",
     "phpunit/phpcov": "^5.0",
     "zendframework/zend-servicemanager":"~3.3",
     "twig/twig": "^2.6",