Created subclass unittest.TestCase for partition-table test

Please review it
Thanks
`test_create_ptable` and `test_update_ptable` both contain an identical dict:

```python
args = {
    'name': self.name,
    'os-family': 'Redhat',
    'file': self.file.name,
    'content': self.content,
}
```

This common code can be thrown into `setUp` too. When constructing this dict, you're doing so locally. You never talk to the server when constructing this dict, and there is no possibility of this statement failing.