Constants wrong for LIFX Mini Day & Night

I noticed the minimum Kelvin value is set to `2500`:
```js
{
  HSBK_MINIMUM_KELVIN: 2500,
  HSBK_DEFAULT_KELVIN: 3500,
  HSBK_MAXIMUM_KELVIN: 9000,
}
```

But the LIFX Mini Day & Night bulbs go down to 1500K and only up to 4000K. In this case, I think there might need to be another set of constants depending on the bulb type.