Expected Behaviour

I'd like to be able to specify a local file on disk for the function store to test out definitions before publishing them on GitHub.

Current Behaviour

I can test any HTTP url via --url, but not a local file via a flag.

Why do you need this?

Better testing experience and contributing experience.

Which Solution Do You Recommend?

A new flag perhaps, or a url like file://. I think a flag fits better with the intuitive developer experience of a UNIX CLI.

Steps to Reproduce (for bugs)

1. git clone https://github.com/openfaas/store-functions && cd store-functions
2. faas-cli store deploy --file ./functions.json
3. See an error