Added two tests for activation key copy

First test verifies that you cannot use a name already taken.
Second test verifies that subscriptions are being copied over.
```
@Test: Copy activation key with duplicate name ... ok
@Test: Copy Activation and verify contents ... ok
```
Bonus: Added the beginings of an activation key search.
I do like to avoid single-use variables, but I also like clear code. What do you two think of this?

```python
self.assertIn(
    subscription_result.stdout[0]['name'],  # subscription name
    result.stdout[3]  # subscription list
)
```