React-SDK - 2.4.0

## [2.4.0] - November 2nd, 2020
Upgrade `@optimizely/optimizely-sdk` to [4.4.0](https://github.com/optimizely/javascript-sdk/releases/tag/v4.4.0):
- Added support for upcoming application-controlled introduction of tracking for non-experiment Flag decisions. See [@optimizely/optimizely-sdk Release 4.4.0](https://github.com/optimizely/javascript-sdk/releases/tag/v4.4.0) for more details.

### New features
- Add UMD and System build targets, available at `dist/react-sdk.umd.js` and `dist/react-sdk.system.js`, respectively ([#80](https://github.com/optimizely/react-sdk/pull/80))

### Bug fixes
- Fix `logOnlyEventDispatcher` to conform to `EventDispatcher` type from @optimizely/optimizely-sdk ([#81](https://github.com/optimizely/react-sdk/pull/81))
- Change the file extension of the ES module bundle from .mjs to .es.js. Resolves issues using React SDK with Gatsby ([#82](https://github.com/optimizely/react-sdk/pull/82)).


https://github.com/optimizely/react-sdk/releases/tag/2.4.0