The DELETE API returns different statuses.

Noticed that the DELETE API returns different http status codes
depending on the entity being deleted and whether the task is
sync/async. For the time being, I have updated the ``delete`` test for
all entities to handle all variations.

```bash
$ nosetests -c robottelo.properties -m test_delete tests/foreman/api/test_multiple_paths.py
nose.config: INFO: Ignoring files matching ['^\\.', '^_', '^setup\\.py$']
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok
@Test Create an entity, fetch it, DELETE it, and fetch it again. ... ok

----------------------------------------------------------------------
XML: /Users/omaciel/hacking/robottelo/foreman-results.xml
----------------------------------------------------------------------
Ran 9 tests in 32.727s

OK
```
Merge pull request #1114 from omaciel/delete-api

The DELETE API returns different statuses.