update setup

• build: remove composer.lock from template
• build: add WP Desk as package author
• build: declare latest low support version
• build: remove composer's platform check
• build: add phpstan as direct dependency/update phpunit
• refactor: update phpunit setup and example test
• build: update phpstan config

composer.json

@@ -32,7 +32,8 @@
 			"cweagans/composer-patches": true,
 			"wpdesk/wp-codeception": true,
 			"wpdesk/wp-wpdesk-composer": true,
-			"kylekatarnls/update-helper": true
+			"kylekatarnls/update-helper": true,
+			"phpstan/extension-installer": true
 		},
 		"platform-check": false
 	},
@@ -45,8 +46,11 @@
 	},
 	"require-dev": {
 		"10up/wp_mock": "*",
-		"phpunit/phpunit": "<7",
+		"phpstan/extension-installer": "^1.3",
+		"phpstan/phpstan": "^1",
+		"phpunit/phpunit": "^8 | ^9",
 		"roave/security-advisories": "dev-latest",
+		"szepeviktor/phpstan-wordpress": "^1.3",
 		"wpdesk/wp-builder": "^2.0.0",
 		"wpdesk/wp-codeception": "^2.7.4",
 		"wpdesk/wp-plugin-flow-free": "^1.0.2",