Add support for PHPCodeSniffer Composer Installer (#1)

* Add support for PHPCodeSniffer Composer Installer

This "type" property is required for the PHPCodeSniffer Composer Installer package to automatically install the ruleset into phpcs. 

https://github.com/Dealerdirect/phpcodesniffer-composer-installer#developing-coding-standards

https://github.com/Dealerdirect/phpcodesniffer-composer-installer/wiki/Change-%60composer.json%60-%22type%22-to-%60phpcodesniffer-standard%60

* Use the existing 'type' property

There is no need to add another :)

composer.json

@@ -1,6 +1,6 @@
 {
     "name": "emielmolenaar/phpcs-laravel",
-    "type": "library",
+    "type": "phpcodesniffer-standard",
     "description": "PHPCS libraries and configuration for Laravel",
     "keywords": [
         "phpcs",