Warning: key is not a prop

[groupsky]

After upgrading I get the warning from react about using a special prop:

      Warning: InfiniteScroll: `key` is not a prop. Trying to access it will result in `undefined` being returned. If you need to access the same value within the child component, you should pass it as a different prop. (https://fb.me/react-special-props)

Introduced in #88, but it is always undefined. The reason the list is refreshed, is because the parent component will recreate the InfiniteScroll on change of key.

[daggmano]

Can this property be renamed to dataSetId or dataKey (or something else) rather than key? And for ease of use change type to string | number, as with React's key attribute.

[ankeetmaini]

PRs welcome!

[daggmano]

Turns out that adding the key prop was not actually necessary in the first place. React automatically re-creates the component on key change anyway...