Time for a v1.0.0

[fotinakis]

Note to self, it's time to release a 1.0 release, since this is definitely being used in production in many places.

Need to identify if there are any blockers to this happening, or if we should just do it.

[fotinakis]

It's confusing right now because semantic versioning dictates that we go from "v0.12.0" to "v0.13.0" for a small backwards-compatible feature addition, and then people have to use ">0.12" as the "safe" version pin. After a 1.0, users could use ">1.0" in order to get >= 1.0 but < 2, which I think is clearer.

I'll probably just do this soon, since we're in a pretty good spot and already make changes in backwards-compatible ways.

The only thing I really want to clean up before 1.0 is the symbol/string potential conflict thing from #47 (comment) — unless anybody out there has strong opinions about other 1.0 necessities.

[fotinakis]

I'm going to just tag a v1.0.0 now since there are a bunch of users of this in prod. No changes from v0.16.2 (what a version number that is!).

[fotinakis]

v1.0.0 launched!