3.0 milestone?

There are two cards, #204 and #181, which reference the 3.0.0 milestone. There are a couple open issues with proposed API changes that we could also put into 3.0, that way we're making API changes on a major release.

Do we have an idea of what we want 3.0 to look like? Now there are enough open suggestions and cards, it might be good to finalize what we want 3.0 to look like so we can let those open issues start moving forward without a minor release.

// cc @cristaloleg @janisz