keepInMemory + serve?

[mnpenner]

Is your feature request related to a problem? Please describe.
If I set keepInMemory: true because I'm using webpack-dev-server, presumably my webpack-assets.json will be served by WDS at some URL... right? How do I access it?

Describe the solution you'd like
path and filename refer to paths on disk; maybe add publicPath to choose where it'll be served from...?

Describe alternatives you've considered
LeavedevServer.contentBase unset, and keepInMemory: false so that assets-webpack-plugin will write the file to disk and then WDS will serve it.

Additional context
I want to set devServer.contentBase to false because I have no need to serve uncompiled assets. I'd also like to set keepInMemory: true because of my setup it'd be too difficult to access from disk anyway, so I just want WDS to serve at some address, like http://localhost:8081/webpack-assets.json.