Add executable file activestorage/bin/test

```
rails$ cd activestorage/
rails/activestorage$ bin/test
........(compressed)....
rails/activestorage$ bin/test test/controllers/disk_controller_test.rb
.(compressed)..
rails/activestorage$ bin/test test/controllers/disk_controller_test.rb:42
.
```

Author: bogdanvlviv

activestorage/bin/test

@@ -0,0 +1,5 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+COMPONENT_ROOT = File.expand_path("..", __dir__)
+require_relative "../../tools/test"