The status API allows external services to mark commits with a success,

failure, error, or pending `state`, which is then reflected in pull requests involving

those commits.

Statuses can also include an optional `description` and `url`, and

we highly recommend providing them as they make statuses much more

useful in the GitHub UI.

As an example, one common use is for continuous integration

services to mark commits as passing or failing builds using Status. The

`target_url` would be the full url to the build output, and the

description would be the high level summary of what happened with the

build.