Add support for asynchronous encryption

[maxdeviant]

Asynchronous support was previously added in #5.

However, it was never fully working properly, as redux-persist does not support asynchronous transforms. Support for asynchronous transforms is tracked by rt2zz/redux-persist#303.

Once redux-persist supports asynchronous transforms then so can redux-persist-transform-encrypt.

[allindeveloper]

I'm currently facing an issue with this.. please a solution would be really helpful

[maxdeviant]

@allindeveloper We can't add asynchronous encryption until redux-persist supports asynchronous transforms, so unfortunately this is blocked until that time.

It looks like redux-persist is not being actively developed anymore. The last commit to the repo was in September 2019.

[Mihai-github]

Hei, any update regarding the async matter? Or has anyone found a solution on how to pass to the encryptTransform function an async secretKey ?

Thanks