soffes/hue — pull request #9 by shokai (2013-10-10 06:13:33+00:00)
Title: bugfix setter of light.saturation and light.brightness

Hi, thank you for a great gem.

I have found a bug and fixed it.

### bug
following code sets random values to hue, but `saturation` and `brightness` are not worked.
```ruby
require 'hue'

hue = Hue::Client.new
hue.lights.each do |light|
light.on = true
end

loop do
hue.lights.each do |light|
puts light.name
light.hue = rand 65535
light.saturation = rand 255 ## not work
light.brightness = rand 255 ## not work
end
sleep 0.1
end
```

they got error messages from hue bridge.
```
"[{\"error\":{\"type\":6,\"address\":\"/lights/1/state/brightness\",\"description\":\"parameter, brightness, not available\"}}]"
"[{\"error\":{\"type\":6,\"address\":\"/lights/2/state/saturation\",\"description\":\"parameter, saturation, not available\"}}]"
```

### fixed
use `STATE_KEYS_MAP` instead of `KEYS_MAP` in translate_keys function.