Event Handlers Don't Update

I'm using 2.3.0 and noticed that the code doesn't account for an event handler prop changing. So, for instance, if I have a component with:

const MyComponent = ({ someCallback }) => (
   <Plot
     data={data}
     onRelayout={someCallback}
   />
);

The someCallback that is called is the first one. Here's a Codepen reproducing:

https://codepen.io/gonzofish/pen/OevOjx

To see it in action, just click autoscale on the chart and you'll see the message change to "Callback 1 Reporting In". If you change the callback by clicking "Change to 2" and then clicking autoscale again, the message doesn't change, despite the callback being changed.

I believe the issues stems from syncEventHandlers only account for two modes: (1) the handler isn't already set but has been provided as a prop and (2) the handler was set but the prop is not longer there. That starts at:

https://github.com/plotly/react-plotly.js/blob/master/src/factory.js#L212

Start in src/factory.js around line 212, where syncEventHandlers handles plot event props, and use the linked CodePen reproduction to observe the callback change. Done means changing the onRelayout prop causes the next autoscale event to invoke the new callback rather than the original one.