This adds a feature where maintainers can add themselves to an array in the source to receive notifications whenever the target fails.
The way this works is via GitHub, I created a new repository https://github.com/Noratrieb/does-it-build-notifications where an app will create issues that ping the respective users. This is the easiest option for me and also fits nicely into people's workflows on GitHub.
Whenever a target fails, an issue is created for it. This issue is kept open (with a new comment every day that it continues to fail), and then closed when the target builds again.
