Add .phpstan.neon, ignore phpstan error for now

.gitattributes

@@ -1,7 +1,7 @@
 /.docker            export-ignore
 /.gitattributes     export-ignore
 /.gitignore         export-ignore
-/.travis.yml        export-ignore
+/.phpstan.neon      export-ignore
 /docker-compose.yml export-ignore
 /docs               export-ignore
 /phpunit.xml        export-ignore

.github/workflows/phpstan.yml

@@ -33,4 +33,4 @@ jobs:
         uses: "ramsey/composer-install@v2"
 
       - name: Run PHPStan
-        run: vendor/bin/phpstan.phar analyze src --level 8
+        run: composer run phpstan

.phpstan.neon

@@ -0,0 +1,29 @@
+parameters:
+	level: 8
+
+	paths:
+		- src/
+
+	scanDirectories:
+		- vendor
+
+	ignoreErrors:
+		-
+			message: "#^Class Art4\\\\JsonApiClient\\\\Helper\\\\AccessKey extends generic class SplStack but does not specify its types\\: TValue$#"
+			count: 1
+			path: src/Helper/AccessKey.php
+
+		-
+			message: "#^Property Art4\\\\JsonApiClient\\\\V1\\\\ResourceNull\\:\\:\\$data is never read, only written\\.$#"
+			count: 1
+			path: src/V1/ResourceNull.php
+
+		-
+			message: "#^Property Art4\\\\JsonApiClient\\\\V1\\\\ResourceNull\\:\\:\\$manager is never read, only written\\.$#"
+			count: 1
+			path: src/V1/ResourceNull.php
+
+		-
+			message: "#^Property Art4\\\\JsonApiClient\\\\V1\\\\ResourceNull\\:\\:\\$parent is never read, only written\\.$#"
+			count: 1
+			path: src/V1/ResourceNull.php

composer.json

@@ -31,7 +31,7 @@
         }
     },
     "scripts": {
-        "phpstan": "phpstan analyze src --memory-limit 512M --level 8",
+        "phpstan": "phpstan analyze --memory-limit 512M --configuration .phpstan.neon",
         "phpunit": "phpunit"
     },
     "config": {