hybridgroup/artoo-gpio — pull request #13 by hqmq (2014-04-26 03:15:31+00:00)
Title: fix passing range configuration to a servo

I could not find a way to pass a custom safe angle range to a servo. I experimented with code like this:

```ruby
device :servo, :driver => :servo, :pin => 1, :range => {:min => 0, :max => 180}
```

But the params I specify get nested under :additional_params like this:

```ruby
{
:parent=> #,
:additional_params=> {
:name=> :servo,
:driver=> :servo,
:pin=> 1,
:range=> {:min=>0, :max=>180},
:parent=>#
}
}
```

I followed the pattern found in https://github.com/hybridgroup/artoo-gpio/blob/master/lib/artoo/drivers/motor.rb#L14