add on rehash on login

Author: taylorotwell

config/hashing.php

@@ -51,4 +51,17 @@
         'verify' => true,
     ],
 
+    /*
+    |--------------------------------------------------------------------------
+    | Rehash On Login
+    |--------------------------------------------------------------------------
+    |
+    | Setting this option to true will tell Laravel to automatically rehash
+    | the user's password during login if the configured work factor for
+    | the algorithm has changed, allowing graceful upgrades of hashes.
+    |
+    */
+
+    'rehash_on_login' => true,
+
 ];