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

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

1.  Now `ContentViewVersion.promote()` and `ContentView.publish()` now wait until the job is finished when synchronous is set to True and returns a `task_id`.

2. This `task_id`, is then used to check the status via the ForemanTask. 

3. `_publish` and  `_promote`  are wrappers around 1. and 2. , which helps in reducing code. Atleast 2-4 lines of code is replaced with _publish or _promote code.

4. When I fixed one or two weeks back I fixed _publish and _promote, at that time these functions where used to wait until the job is finished, which is now removed. Now that(wait until the job)  is done by `ContentViewVersion.promote()` and `ContentView.publish()`. But they still exist because of the reason mentioned in 3.

I think that explains all now. :)