#33 Add support for non Drupal 8 projects

Code Quality tool needs PHP iconv module enabled but
it's not always available by default. That's why
Drupal 8 has added polyfill package for it and it
makes sense to add it to Code Quality too. We want
this tool to be installed as easily as possible.

composer.json

@@ -31,6 +31,7 @@
     ],
     "bin": ["bin/check_perms"],
     "require": {
+        "symfony/polyfill-iconv": "^1",
         "phpro/grumphp": "^0.16.0",
         "drupal/coder": "^8",
         "phpcompatibility/php-compatibility": "^9.3",
@@ -42,6 +43,9 @@
         "mglaman/phpstan-drupal": "^0.11.1",
         "phpstan/phpstan-deprecation-rules": "^0.11.0"
     },
+    "provide": {
+        "ext-iconv": "*"
+    },
     "autoload": {
         "psr-4": {
             "Wunderio\\GrumPHP\\": "src/"