fog/fog — pull request #2725 by eLobato (2014-03-03 18:30:35+00:00)
Title: [Openstack|Volumes] available? check method

available? simply returns whether the volume is being used or its
available. This is convenient for applications using the Fog API to
check if they can use a Volume by calling

```ruby
openstack.volumes.select(&:available)
```