Default RemoteFetch constructor always throws exception

[gamringer]

The default declaration of RemoteFetch always throws a FilesystemException because $dataDir is empty. I think $dataDir should be a mandatory argument or have a default value of ".". What do you think.

It occured when using https://github.com/paragonie/quill with the default $http constructor argument. I stumbled upon this when trying the example from the Quill Readme on PHP 7.2.18

[paragonie-scott]

I think making it mandatory makes sense.