[ BugFix ] Ensure executable on update (#79)

* Adds Hook::ensureExecutable() method

* ensure that updated hooks are executable

Author: ProjektGopher

app/Commands/Update.php

@@ -35,6 +35,7 @@ public function handle(): int
             }
 
             $hook->install();
+            $hook->ensureExecutable();
 
             if ($this->option('verbose')) {
                 $this->info("{$hook->name} git hook installed successfully.");

app/Hook.php

@@ -85,6 +85,16 @@ public function enable(): void
         File::put(Platform::cwd(".git/hooks/{$this->hook}"), '#!/bin/sh'.PHP_EOL);
     }
 
+    /**
+     * Ensure the hook is executable.
+     */
+    public function ensureExecutable(): void
+    {
+        if ((new Platform)->isNotWindows()) {
+            exec('chmod +x '.Platform::cwd(".git/hooks/{$this->hook}"));
+        }
+    }
+
     /**
      * Checks if the hook uses Whisky.
      */