Drop support for purescript-simple-json

[joneshf]

There's two reasons for dropping support for purescript-simple-json: the maintainer is actively abrasive, and it's not a "library."

The first point is a non-technical reason, but the more important reason. I personally don't feel like integrating with a package when that maintainer is so abrasive. I get that people have different ways of maintaining code. I mean, I don't accept contributions to purty because I can't deal with them. But, this sort of interaction is a bit much:

• update to 0.14 -> fix "Module Global.Unsafe was not found" justinwoo/purescript-simple-json#78 (comment)
• Replace all instances of SProxy with Proxy and remove purescript-type… justinwoo/purescript-simple-json#83 (comment)
• Pull requests not accepted from "fake accounts"? justinwoo/purescript-simple-json#84 (comment)

Supporting these sorts of interactions–even passively by keeping the integration in this package–just reinforces that this behavior is acceptable. And nobody should find this sort of behavior acceptable; I sure don't. This is motivation enough to drop support.

The second point is a technical reason not to support purescript-simple-json. The intent of supporting different packages is to make it easier to use them with this package. But, that's not really the way purescript-simple-json is supposed to be used. It's got a different workflow it pushes, and that's fine. That workflow doesn't really line up with how things work in this package though.

This is a breaking change, since we're dropping support for an entire package. So, we'll have to do a major release.