AppImage for Ruby

Hey
I noticed there is no guide for Building for Ruby.
Is it possible?

I have a simple ruby-gtk2 app, built with green_shoes gem. It is simply an abstraction layer on top of ruby-gtk2. But the thing is I have heavily modified the source of green_shoes.
So question,
1. how can I build a AppImage for a ruby based app which has external dependencies, gems hosted somewhere ?
2. how can I use the local version of green_shoes gem (or local dependencies/dirs/gems), and create an AppImage for my ruby app?