Update dependencies version

Author: na2axl

composer.json

@@ -22,8 +22,8 @@
     "php": "^7.1.10"
   },
   "require-dev": {
-    "phpunit/php-code-coverage": "~1.2.1",
-    "phpunit/php-file-iterator": ">=1.3.0@stable"
+    "phpunit/php-code-coverage": "^6.0.4",
+    "phpunit/php-file-iterator": "^1.4.5"
   },
   "autoload": {
     "psr-4": {