i think it's happening due to following reason:

1) Make sure you have added correct repository name  in odoo app store?

2) You added #12.0 in repository name, so have to create branch named as 12.0 in your repository and push all code to that branch so that odoo can read that code.
3) If your repository is private then you have to give read permission to odoo user.

4) make sure you have to add your module in root folder in your repository.

For reference just read upload guideline \Submit App

hope it will useful for you..