No implementation of MockStorageReference.getDownloadURL

[ChopinDavid]

I've gone ahead and forked this repo and implemented getDownloadURL within MockStorageReference. It seems that there is no way, AFAIK, to construct a download url that is similar to an actual Firebase Storage download URL (https://firebasestorage.googleapis.com/v0/b/{your-application}.appspot.com/o/{url-encoded-path-name}?alt=media&token={your-token}) so I have it returning a dummy value instead (https://firebasestorage.googleapis.com/{path}). This dummy value could be updated so that _path is url encoded when interpolated into the download URL path that the function returns. Also, there could probably also be a test written around this, but I didn't see any Mock Reference tests.

Let me know if you are interested in me creating a PR for my fork.

[cedvdb]

yes the pr would be nice