link to something from camelus notifications on GitHub tests

[agarwal]

Pull requests to opam-repository show up with info like the screen shot below. It would be helpful to get more info somehow. For example, travis tests provide a link pointing to a log of what was run. If nothing else, at least point to this repo and update the README of this repo to provide more information about what is checked.

[AltGr]

Indeed, thanks for pointing this out!