Add support for Job Hook

[mutezero]

Low priority for us, but it would be nice to have.

Currently this kind of events is rejected by Yappy with HTTP status 403 and response body: Invalid data. Plz use Gitlab webhooks.

X-Gitlab-Event is Job Hook

{
  "object_kind": "build",
  "ref": "develop",
  "tag": false,
  "before_sha": "0123456789012345678901234567890123456789",
  "sha": "0123456789012345678901234567890123456789",
  "build_id": 1,
  "build_name": "build-linux",
  "build_stage": "build",
  "build_status": "canceled",
  "build_started_at": null,
  "build_finished_at": "2018-07-11 09:12:45 UTC",
  "build_duration": null,
  "build_allow_failure": false,
  "build_failure_reason": "unknown_failure",
  "project_id": 1,
  "project_name": "My Test Team / My Test Project",
  "user": {
    "id": 1,
    "name": "UserName",
    "email": "[email protected]"
  },
  "commit": {
    "id": 1,
    "sha": "0123456789012345678901234567890123456789",
    "message": "Merge remote-tracking branch 'remotes/origin/master' into develop\n",
    "author_name": "UserName",
    "author_email": "[email protected]",
    "author_url": "https://git.xpenia.games/iamthezero",
    "status": "canceled",
    "duration": null,
    "started_at": null,
    "finished_at": "2018-07-11 09:12:46 UTC"
  },
  "repository": {
    "name": "My Test Project",
    "url": "[email protected]:my-team/test-project.git",
    "description": "",
    "homepage": "https://gitlab.example.host/my-team/test-project",
    "git_http_url": "https://gitlab.example.host/my-team/test-project.git",
    "git_ssh_url": "[email protected]:my-team/test-project.git",
    "visibility_level": 20
  }
}```

[dsevillamartin]

It no longer errors, now it just needs styling.