Future of kue

Hi everybody,

I use `kue` in various projects for French government.
I open this issue because I need a bit of visibility on the maintenance and the next evolutions.

Some points:
* @behrad is announcing a `v1` since more than one year. As I can see on the `v1` branch, it is still a WIP. It blocks any ambitious PR. How can we help to target a quick release?
* Parts of the library are staled (UI, API).
* Other similar projects (as https://github.com/agenda/agenda) are pretty active.

I have the feeling that the actual kue is too big to be efficiently embedded in high-level libraries, and a bit too small to cover advanced use cases.

In the past I slightly modified `kue` and published `kue-lite` for our internal usage, and we are now working on a wrapper around `kue` which support job unicity, promises, add advanced logging, job configuration with YAML or JSON file and out-of-the-box jobs worker. Maybe some of these features would have their place in `kue`.

It could be interesting to have a package `kue-core` with just the logic and connection to Redis, and a full-featured kue with JSON API and UI. And why not `kue-ui`, `kue-websocket`, `kue-api`, `kue-webhooks`…

Feel free to discuss my position ;)

The issue names the v1 branch and the existing UI/API, so begin by reviewing those and the current kue structure. Its proposed kue-core and companion packages are architectural options rather than a defined task; done is not specified and would require a maintainer decision.

Written by the indexing model from the issue text.