Add code coverage and test badges?

[EyalLavi]

Are we going to re-add badges or other indicators for code coverage and test success as separate from build success in the future? E.g. coveralls would be nice for code coverage.

[MikeSmithEU]

I would love this project to be setup with coveralls! For the moment this is not something I can spend time on but I would encourage any PRs that accomplish this.