Add some PHPCS corrections

app/code/backup/Folder.php

@@ -4,41 +4,40 @@ namespace Shikiryu\Backup\Backup;
 
 class Folder extends BackupAbstract
 {
-
     public function __construct(array $config = array())
     {
         parent::__construct($config);
     }
 
     /**
-     * @return bool
-     */
+    * @return bool
+    */
     public function isValid()
     {
         // TODO: Implement isValid() method.
     }
 
-	/**
-	 * Function that can be used to initialize the backup
-	 */
+    /**
+    * Function that can be used to initialize the backup
+    */
     protected function preBuild()
     {
         // TODO: Implement preBuild() method.
     }
 
-	 /**
-	 * Function that can be used after the backup
-	 */
+    /**
+    * Function that can be used after the backup
+    */
     protected function postBuild()
     {
         // TODO: Implement postBuild() method.
     }
 
-	/**
-	 * Mandatory function doing the backup
-	 */
+    /**
+    * Mandatory function doing the backup
+    */
     protected function build()
     {
         // TODO: Implement build() method.
     }
-}
+}