`subscribeToChanges` always uses camelCase

[enceeobee]

Hello 👋 ,

First, thank you for this package! It's wonderful 😄

Issue

I recently noticed that subscribeToChanges always uses a camelCase flag key when updating the store, even when useCamelCaseFlagKeys is set to false.

I don't think the fix should be too difficult, and I can probably supply a PR for it soon, but I wanted to open an issue for posterity.

Steps to reproduce

1. init ld-redux setting useCamelCaseFlagKeys to false

     ldRedux.init({
       clientSideId: 'your-client-side-id',
       dispatch: store.dispatch,
       useCamelCaseFlagKeys: false
     });

2. Later, identify a new user, which will dispatch an event(s) to update the store once the new flag values are ready

     window.ldClient.identify({key: 'someUserId'});

3. Observe that the flag key in the SET_FLAG action is incorrectly sent in camelCase (e.g. 'my-kebab-case-flag' is updated as 'myKebabCaseFlag')

Screenshots

Here's an example of a flag being updated in camelCase, when it should be kebab-case

[yusinto]

The fix for this has been merged and released in v3.3.4.