feat(storageActions): support firebase.storage.SettableMetadata on upload

[qalqi]

Do you want to request a feature or report a bug?

After files are being uploaded with react-redux-firebase we need to provide settablemetadata for cacheControl to ensure files are not repeatedly downloaded again. Here is API reference from firebase https://firebase.google.com/docs/reference/js/firebase.storage.SettableMetadata#cacheControl

[qalqi]

Your work and this project are great. Are you looking to add contributors?

[prescottprue]

@qalqi Thank you! And yes, looking to add contributors. Also, as always, open to pull requests.

This feature should be able to be added without breaking, but just to note: there has been some talk in #368 about breaking changes that will most likely be making it into v3.0.0.