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

@@ -25,7 +25,7 @@
 		"autoloader-suffix": "PluginTemplate",
 		"sort-packages": true,
 		"platform": {
-			"php": "7.2.32"
+			"php": "7.3.20"
 		},
 		"allow-plugins": {
 			"dealerdirect/phpcodesniffer-composer-installer": true,
@@ -40,7 +40,7 @@
 	"prefer-stable": true,
 	"minimum-stability": "stable",
 	"require": {
-		"php": ">=7.2 | ^8",
+		"php": ">=7.3 | ^8",
 		"psr/log": "^1.1.4",
 		"wpdesk/wp-wpdesk-helper-override": "^1.1.0"
 	},
@@ -67,7 +67,7 @@
 		"po-files": {
 			"pl_PL": "pl_PL.po"
 		},
-		"php-requires": "7.2"
+		"php-requires": "7.3"
 	},
 	"scripts": {
 		"test": "echo composer is alive",