Merge this into gocraft/work about work HOT 4 OPEN

@austintaylor sgtm. but I don't have a good migration plan. do you have time to work on this?

from work.

If that is the only issue, it may not be such a problem: not having compatibility is part of creating a major version. As long as there is a doc detailing all the API changes (not just the new API), I would say it is fine, even though it is not optimal. Better done than perfect.

from work.

just put the old stuff on v1 branch and merge this into master, we'll get a ton more support for this

from work.

Another major problem is that I don't have the time for answering questions on github. In old gocraft/work, there will be a lot of existing users asking about how to migrate. This is a primary reason why I didn't do that yet.

This library is mature enough: we run 10-50 millions jobs with this a day internally. It covers various workloads with custom middleware: some are 1hour+ long-running jobs, and some require extremely small latency like 100ms. It is very battle-tested, but it lacks good docs and examples. I think you can use this library now even it is not merged to gocraft/work yet.

from work.