proxy: add background worker to fetch requested modules that aren't present locally

[bketelsen]

No description provided.

[arschles]

excellent idea. for production-like deployments we'll want the worker queue to be backed by not-memory. we should write a grift that we can run separately that consumes the queue

[arschles]

I talked to someone yesterday that uses https://github.com/gocraft/work a lot. If the standard buffalo background worker isn't enough for us, this would be a good option. Putting here as a reminder for later if we need it.

[ghost]

could this be solved by #132 or #182

[michalpristas]

closing