(docs): Update README with redux-persist-expo-securestore (#678)

README.md

@@ -197,6 +197,7 @@ The createTransform function takes three parameters.
 - **[redux-persist-filesystem-storage](https://github.com/robwalkerco/redux-persist-filesystem-storage)** react-native, to mitigate storage size limitations in android ([#199](https://github.com/rt2zz/redux-persist/issues/199), [#284](https://github.com/rt2zz/redux-persist/issues/284))
 - **[redux-persist-node-storage](https://github.com/pellejacobs/redux-persist-node-storage)** for use in nodejs environments.
 - **[redux-persist-sensitive-storage](https://github.com/CodingZeal/redux-persist-sensitive-storage)** react-native, for sensitive information (uses [react-native-sensitive-storage](https://github.com/mCodex/react-native-sensitive-info)).
+- **[redux-persist-expo-securestore](https://github.com/Cretezy/redux-persist-expo-securestore)** react-native, for sensitive information using Expo's SecureStore. Only available if using Expo SDK (Expo, create-react-native-app, standalone).
 - **[redux-persist-fs-storage](https://github.com/leethree/redux-persist-fs-storage)** react-native-fs engine
 - **[redux-persist-cookie-storage](https://github.com/abersager/redux-persist-cookie-storage)** Cookie storage engine, works in browser and Node.js, for universal / isomorphic apps
 - **custom** any conforming storage api implementing the following methods: `setItem` `getItem` `removeItem`. (**NB**: These methods must support promises)