API Content Views with yum repo test cases - issue #1265

implements 4 tests cases - issue #1265 

all 4 tests are ok 

OK, let's take a good look at each of these two methods, starting with `_publish`. Here's the source of `_publish`:

```python
 task_id = entities.ContentView(id=content_view['id']).publish()
return entities.ForemanTask(id=task_id).poll()['result']
```

And here's the source of the actual `ContentView.publish` method:

```python
        response = client.post(
            self.path('publish'),
            auth=get_server_credentials(),
            verify=False,
            data={u'id': self.id}
        )
        response.raise_for_status()

        # Return either a ForemanTask ID or None.
        if response.status_code is httplib.ACCEPTED:
            task_id = response.json()['id']
            if synchronous is True:
                ForemanTask(id=task_id).poll()
            return task_id
        return None
```

It appears to me that the `_publish` method does nothing for us. It polls the task ID returned by `publish`, which is redundant.