allowFloat: Boolean - defaults to true. Specify false to only allow integers
allowNegative: Boolean - defaults to true
minValue
maxValue
step: Number - defaults to 1
shiftStep: Number - defaults to 10
stepDelay: Number - defaults to 40 ms
stepOnWheel: Boolean - defaults to true
requireFocusOnStep: Boolean - defaults to true
numbersOnly: Boolean - defaults to true
factory: Function - another React factory to render a different component. By default, a react-field is rendered.
onChange(value, event) - By default, the onChange handler will be called with the value as the first arg. If you use a factory function that calls onChange with other args, those will be passed to the onChange.