Typescript Defs might need update.

Hi Plotly-React, 

I think this is a minor issue, but it seems that the Typescript definations are not updated.
I am using the latest version, but Typescript is complaining when I try to use onRelayouting - thereby not allowing me to compile the code. 
But the following work, 
```
// @ts-ignore
onRelayouting={(e) => console.log('onRelayouting', e) }
```

Thanks for the great library. 