Attempt to display the volume name as description in OS X
Attempt to display the volume name as description in OS X

The `Volume Name` key contains a much more human friendly description
for the drive. This PR attempts to use is over `Device / Media Name`
unless its not applicable. For example

```
Volume Name:              Not applicable (no file system)
```

Fixes: https://github.com/resin-io-modules/drivelist/issues/88
Signed-off-by: Juan Cruz Viotti <4148f5869aa1bcd7efd85b513a5874967e585032@openmailbox.org>

resin-io/drivelist,resin-io/drivelist,resin-io-modules/drivelist,resin-io-modules/drivelist,resin-io-modules/drivelist,resin-io-modules/drivelist