External machines can now notify Hydra that it should check a
repository by sending a GET or PUSH request to /api/push, providing a
list of jobsets to be checked and/or a list of repository URLs. In
the latter case, all jobsets that have any of the specified
repositories as an input will be checked.
For instance, you can configure GitHub or BitBucket to send a request
to the URL
http://hydra.example.org/api/push?repos=git://github.com/NixOS/nixpkgs.git
to trigger evaluation of all jobsets that have
git://github.com/NixOS/nixpkgs.git as an input, or to the URL
http://hydra.example.org/api/push?jobsets=patchelf:trunk,nixpkgs:trunk
to trigger evaluation of just the specified jobsets.
