Names of coding standards should prefixed by "@" in v2 of PHP-CS-Fixer

Error:
In ConfigurationResolver.php line 755:
The rules contain unknown fixers: "PSR2".

Author: mmarynich

src/PhpGitHooks/Module/PhpCsFixer/Contract/Command/PhpCsFixerToolHandler.php

@@ -45,19 +45,19 @@ public function __construct(OutputInterface $output, PhpCsFixerToolProcessorInte
     private function execute(array $files, $psr0, $psr1, $psr2, $symfony, $options, $errorMessage)
     {
         if (true === $psr0) {
-            $this->executeTool($files, 'PSR0', $options, $errorMessage);
+            $this->executeTool($files, '@PSR0', $options, $errorMessage);
         }
 
         if (true === $psr1) {
-            $this->executeTool($files, 'PSR1', $options, $errorMessage);
+            $this->executeTool($files, '@PSR1', $options, $errorMessage);
         }
 
         if (true === $psr2) {
-            $this->executeTool($files, 'PSR2', $options, $errorMessage);
+            $this->executeTool($files, '@PSR2', $options, $errorMessage);
         }
 
         if (true === $symfony) {
-            $this->executeTool($files, 'SYMFONY', $options, $errorMessage);
+            $this->executeTool($files, '@SYMFONY', $options, $errorMessage);
         }
     }