Add endpoint /jenkins/status for posting Jenkins status updates

Example request: 

```
POST /jenkins/status
```

```
{
  "job_name": "ibl",
  "build_number": "25",
  "url": "http://jenkins.bbc.co.uk/job/ibl/331/",
  "status": true
}
```

Message:

```
Jenkins build ibl #25 SUCCESS http://jenkins.bbc.co.uk/job/ibl/331/
```