Add option to skip collating "Attachments" directory

[Cyberbeni]

Feature Request

Add option to skip collating "Attachments" directory during multi_scan

Motivation Behind Feature

We never use the contents of this directory and Xcode 8.2 (for macOS 10.11 testing) doesn't delete the generated Attachments, so it would take up a lot of space, so we run a script using fswatch to remove write permission from directories called Attachments, which makes this copying throw an error.

[lyndsey-ferguson]

I want to apologize that I have not responded to this issue. A family health issue is requiring me to narrow my focus on the essentials and I don't have the time I need to focus on the plugin more than a minute. If you can get some other contributors to this project to help with this, I would consider merging a resulting PR.