Add codestyle dependency.

Author: janbarasek

composer.json

@@ -14,7 +14,8 @@
 	"require-dev": {
 		"phpstan/phpstan": "^0.12.18",
 		"tracy/tracy": "^2.7",
-		"phpstan/phpstan-nette": "^0.12.6"
+		"phpstan/phpstan-nette": "^0.12.6",
+		"symplify/easy-coding-standard": "^8.3"
 	},
 	"autoload": {
 		"classmap": [