Use the Issues in the private repo

[wibeasley]

The code for this project is split between this public repo and the private one. To keep things more consistent for us, let's just use the issues over at https://github.com/OuhscBbmc/Tfcbt/issues.

If you're an external contributor and don't have access to the private repo, please post here. We'd like to include you. Thanks for your interest in our project.