Fix#18, fix#28
* Add support for fan domain
* Fix fan status string when speeds are not numeric
* Add support for input_select domain
* Fan and input_select domains will change the max, min, and scale if all of their options (or speeds) are numeric
* Perform numeric check less often
* Remove numeric mode in favor of cleaner logic
* Change some one-liners to arrow functions
* Fix bug on getter for string based option lists
* Update README.md