Added clone function and test for cloning provisioning template.

`os_1_name` and `os_2_name` are single-use variables. They can be discarded. For example:

```python
os_list = [
    entities.OperatingSystem().create()['name'],
    entities.OperatingSystem().create()['name'],
]
```

Or, even more succinctly:

```python
os_list = [
    entities.OperatingSystem().create()['name'] for _ in range(2)
]
```

Non-blocking comment.