SoCo/SoCo — pull request #166 by lawrenceakka (2014-06-04 16:43:58+00:00)
Title: is_coordinator added

Adding an `is_coordinator` property to check if a zone is the coordinator of its group.

```python
if zone.is_coordinator
```
is easier to type (and runs quicker) than

```python
if zone.group.coordinator is zone:
```