Add support for Composer 2.0

Author: sybrew

composer.json

@@ -26,7 +26,7 @@
 		"wp-coding-standards/wpcs": "^2.3"
 	},
 	"require-dev": {
-		"dealerdirect/phpcodesniffer-composer-installer": "^0.5.0",
+		"dealerdirect/phpcodesniffer-composer-installer": "^0.5.0|^1.0",
 		"phpcompatibility/php-compatibility": "^9.0",
 		"phpunit/phpunit": "^4.0 || ^5.0 || ^6.0 || ^7.0",
 		"sirbrillig/phpcs-variable-analysis": "^2.11.0",