Upgrade to v8 of coding Standard

Author: rdohms

composer.json

@@ -4,7 +4,8 @@
     "type": "library",
     "require": {
         "phpunit/phpunit": "^9.0",
-        "php": "^7.3|^8.0"
+        "php": "^7.3|^7.4|^8.0",
+        "dms/coding-standard": "^8"
     },
     "license": "MIT",
     "authors": [
@@ -14,7 +15,6 @@
         }
     ],
     "require-dev": {
-        "dms/coding-standard": "^1.0",
         "squizlabs/php_codesniffer": "^3.4"
     },
     "autoload": {