enable use of other backends besides express

[noahehall]

• Operating System: ubuntu baby
• Node Version: latest
• NPM Version: latest
• webpack Version: latest
• ${package} Version: latest

Feature Proposal

enable use of other backends besides express, e.g. i use koa2. it could be something like my hacky version here

I had to modify both this project and webpack-dev-middleware but the modifications were so trivial I imagine there could be a simplier way for your consumers to enable this without having to go through the forking like i did.

It would be great to say hey 'use this middleware instead of the default' and supply either my own fn or one available within this repo.

thx!

Feature Use Case