Add mikey179/vfsstream Composer dependency

Author: shochdoerfer

composer.json

@@ -20,13 +20,14 @@
     "phpstan/phpstan": "^0.12.18"
   },
   "require-dev": {
+    "bitexpert/phing-securitychecker": "^0.4.0",
     "captainhook/captainhook": "^5.1.2",
     "captainhook/plugin-composer": "^5.1.3",
+    "mikey179/vfsstream": "^1.6",
     "nikic/php-parser": "^4.3",
-    "phpunit/phpunit": "^8.5.3",
-    "squizlabs/php_codesniffer": "^3.4",
     "phing/phing": "^2.16",
-    "bitexpert/phing-securitychecker": "^0.4.0"
+    "phpunit/phpunit": "^8.5.3",
+    "squizlabs/php_codesniffer": "^3.4"
   },
   "autoload": {
     "files": [