Make the parser Response be public

[drinkbeer]

TL;DR - What are you trying to accomplish?

Expose the Response which is part of the returned hashmap of set_multi API.

Details - How are you making this change? What are the effects of this change?

[nickamorim]

Should we instead change set_multi to return a Result<FxHashMap<&'a K, Result<Status, Error>>, Error>?

[mrattle]

Should we instead change set_multi to return a Result<FxHashMap<&'a K, Result<Status, Error>>, Error>?

I think we get the same information from just simplifying even further to return Result<FxHashMap<&'a K, Result<(), Error>>, Error>. I think the only green-path response that we can get back on a set operation is STORED, and everything else would be parsed into an Err(_) variant. This is matches with how the single set operation is implemented, and would also hold true for the add_multi operation where NOT_STORED can be returned but is parsed as an error.

[mrattle]

Now that #41 is merged, this PR can be closed.