fixed issue #49: Return type of createInstance was OptimizelyReactSDKClient which is the implementation class. Changed it to the ReactSDKClient interface instead (#148).
fixed issue #121:ActivateListenerPayload and TrackListenerPayload types were exported from @optimizely/optimizely-sdk but were missing from @optimizely/react-sdk exports. (#150).
Bug fixes
Fixed issue #134 of the React SDK crashing when the internal Optimizely client returns as a null value. PR #149