Upgrade to allow PHP 8 (#10)

Upgrade for PHP 8
Upgrade doctrine/coding-standard -> ^8.1

Author: Frank Verhoeven

MyOnlineStore/ruleset.xml

@@ -100,10 +100,4 @@
             <property name="spacesCountBeforeColon" value="0"/>
         </properties>
     </rule>
-
-    <rule ref="Squiz.Strings.ConcatenationSpacing">
-        <properties>
-            <property name="spacing" value="0"/>
-        </properties>
-    </rule>
 </ruleset>

composer.json

@@ -5,18 +5,15 @@
     "homepage": "https://github.com/MyOnlineStore/coding-standard",
     "license": "MIT",
     "require": {
-        "php": "^7.2",
-        "dealerdirect/phpcodesniffer-composer-installer": "^0.5",
-        "doctrine/coding-standard": "^7.0",
+        "php": "^7.2 || ^8.0",
+        "dealerdirect/phpcodesniffer-composer-installer": "^0.7",
+        "doctrine/coding-standard": "^8.1",
         "squizlabs/php_codesniffer": "^3.5"
     },
     "require-dev": {
         "roave/security-advisories": "dev-master"
     },
     "config": {
-        "sort-packages": true,
-        "platform": {
-            "php": "7.2.24"
-        }
+        "sort-packages": true
     }
 }