Support for spec final v1.1

.gitignore

@@ -1,2 +1,3 @@
 vendor/
 tests/report/
+.phpunit.result.cache

.scrutinizer.yml

@@ -1,8 +1,12 @@
 build:
   environment:
-    php: 7.4.0
+    php: 8.1
   nodes:
     coverage:
+      environment:
+        php:
+          ini:
+            "xdebug.mode": coverage
       tests:
         override:
           - command: php ./script/test_with_coverage.php

README.md

@@ -156,7 +156,7 @@ Which will result in:
 				"message": "That is not valid",
 				"code": 422,
 				"file": "README.md",
-				"line": 107,
+				"line": 137,
 				"trace": []
 			}
 		}
@@ -166,6 +166,57 @@ Which will result in:
 
 This can be useful for development. For production usage, you can better construct an `ErrorsDocument` with only specific values.
 
+#### Using extensions and profiles
+
+The [Atomic Operations extension](https://jsonapi.org/ext/atomic/) and the [Cursor Pagination profile](https://jsonapi.org/profiles/ethanresnick/cursor-pagination/) come packaged along. Any 3rd party of self-made extension can be applied with:
+
+```php
+use alsvanzelf\jsonapi\ResourceDocument;
+use alsvanzelf\jsonapi\interfaces\ExtensionInterface;
+
+class ExampleExtension implements ExtensionInterface {
+	public function getOfficialLink() {
+		return 'https://example.org/extension-documentation';
+	}
+
+	public function getNamespace() {
+		return 'foo';
+	}
+}
+
+$document = new ResourceDocument('user', 42);
+$document->add('name', 'Zaphod Beeblebrox');
+
+$extension = new ExampleExtension();
+$document->applyExtension($extension);
+$document->addExtensionMember($extension, 'bar', 'baz');
+
+$document->sendResponse();
+```
+
+Which will result in:
+
+```json
+{
+    "foo:bar": "baz",
+    "jsonapi": {
+        "version": "1.1",
+        "ext": [
+            "https://example.org/extension-documentation"
+        ]
+    },
+    "data": {
+        "type": "user",
+        "id": "42",
+        "attributes": {
+            "name": "Zaphod Beeblebrox"
+        }
+    }
+}
+```
+
+A similar flow can be used for profiles.
+
 #### Other examples
 
 Examples for all kind of responses are in the [/examples](/examples) directory.

composer.json

@@ -23,7 +23,7 @@
 		}
 	},
 	"require-dev": {
-		"phpunit/phpunit": "^5.7|^6.5|^7.5|^8.5|^9.4",
+		"phpunit/phpunit": "*",
 		"psr/http-message": "^1.0"
 	},
 	"suggest": {